McGregor Lake Habitat Rehabilitation and Enhancement Project Feasibility Report and Integrated Environmental Assessment

Transcription

1 Main Report McGregor Lake Habitat Rehabilitation and Enhancement Project Feasibility Report and Integrated Environmental Assessment Upper Mississippi River Restoration Program Mississippi River: Mile St. Paul District Project Sponsor: U.S. Fish and Wildlife Service November 2018

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3 EXECUTIVE SUMMARY The McGregor Lake Habitat Rehabilitation and Enhancement Project is located in Pool 10 of the Upper Mississippi River, adjacent to Prairie du Chien, Wisconsin, and Marquette, Iowa (see Figure ES-1). The project area includes McGregor Lake and the associated island, channel and backwater complex between the main channel and east channel. The entire project area is approximately 1,063 acres in size, and lies within the Upper Mississippi River National Wildlife and Fish Refuge. The habitat concerns within the project area center around the general degradation of habitat quality in this region of the river. This degradation is the result of increased minimum water surface elevations which has degraded the floodplain forest community, increased hydraulic connectivity resulting in cold water entering overwintering areas, and sediment deposition in backwater areas. The planning process emphasized the protection and improvement of floodplain forest habitat, and providing quality overwintering habitat for species that rely on backwaters for this life function. Because it is not possible to restore or create ideal habitat conditions for all forms of fish and wildlife, measures were designed and evaluated primarily to improve conditions for Federal and State natural resource agencies priority communities: forest and native fish communities. To identify alternatives, measures were combined in various logical combinations and constraints were imposed to minimize adverse impacts to the environment. The resulting 39 alternatives, as well as the No-Action Alternative, were evaluated in detail by comparing the benefits and costs of each. In addition to the No Action Alternative, nine action alternatives were identified as Best Buy alternatives based on the cost effectiveness and incremental cost analysis using the Institute of Water Resources (IWR) economic analysis program called IWR- Plan. Based on the incremental analysis and other evaluation criteria, Alternative 37 is the Tentatively Selected Plan (TSP) for implementation (Figure ES-2). The TSP improves and/or creates over 380 acres of floodplain forest and aquatic habitat throughout the project area. The TSP is a best buy alternative that yields 125 net average annual habitat units (AAHUs) at an average cost of $5,638 per AAHU (FY2018 price level, FY2018 Federal discount rate of 2.75%, for a 50-year period of analysis). The project first cost for the TSP is $17,714,506. This alternative meets the project objectives and maximizes habitat benefits at a reasonable cost. The TSP is the alternative that best meets the goals and objectives of each agency and the Upper Mississippi River Restoration program. It includes constructing floodplain forest features F8, F4B, F14, F15 and F16 (45.2 acres) through the use of sand and fine material placement up to a maximum elevation of 620 ft. Sand material will come from channel dredging associated with the channel maintenance program. Fine material will come from dredging portions of the identified backwater locations (Executive Figure 2; approximately 270 acres of aquatic habitat benefited). A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. This is accomplished via Floodplain Forest feature F14. The recommended plan includes erosion protection with R2 and R4, as well as an overtopping rock spillway as a part of F14. It includes emergent wetland feature W1, benefiting about 21.5 acres of emergent wetland; flow control structure C1; as well as the Timber Stand Improvement (TSI) for existing floodplain forest areas. ES-I

4 The project would be constructed in phases, likely beginning in It would likely take three to four years to complete basic construction, following by floodplain forest plantings and other management activities. Figure ES.1. Location of McGregor Lake HREP Project Area. ES-II

5 ES.2. McGregor Lake HREP Recommended Plan. ES-III

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7 FEASIBILITY REPORT AND INTEGRATED ENVIRONMENTAL ASSESSMENT MCGREGOR LAKE HABITAT REHABILITATION AND ENHANCEMENT PROJECT POOL 10, UPPER MISSISSIPPI RIVER CRAWFORD COUNTY, WISCONSIN TABLE OF CONTENTS EXECUTIVE SUMMARY... ES-I 1. INTRODUCTION Authority Participants and Coordination Purpose Project Area Resource Significance Decisions To Be Made Selection Process ASSESSMENT OF EXISTING RESOURCES Physical Setting Bathymetry Aquatic and Terrestrial Habitat Water Resources Tributaries Groundwater Flow and Current Velocity Wind and Wave Action Water Quality Land Cover and Planview Conditions Vegetation Fish and Wildlife Resources Cultural Resources Recreation and Aesthetics Socioeconomic Setting Hazardous, Toxic, and Radioactive Waste Historically Documented Changes in Habitat Conditions Factors Influencing Habitat Change DEVELOPMENT OF PROJECT OBJECTIVES Future Without-Project Conditions Resource Problems and Opportunities Project Goals and Objectives Planning Constraints POTENTIAL RESTORATION MEASURES Potential Measures Planning Considerations i

8 5. FEATURE EVALUATION & ALTERNATIVE PLAN FORMULATION Development of Alternatives Evaluation and Comparison of Final Array of Alternatives Plan Selection ENVIRONMENTAL CONSEQUENCES Natural Resources Hazardous, Toxic, and Radioactive Waste Flooding Effects Historical and Cultural Resources Socioeconomic Resources Aesthetics Noise Levels Environmental Justice Greenhouse Gases CUMULATIVE EFFECTS Past, Present, and Future Actions Cumulative Effects to Floodplain Forest Cumulative Effects to Wetland Habitat Cumulative Effects to Fisheries Cumulative Effects to Flood Stage Impacts RECOMMENDED PLAN Recommended Plan Operation, Maintenance, Repair, Rehabilitation, and Replacement Cost Estimate Real Estate Considerations Project Performance (Monitoring and Adaptive Management) PLAN IMPLEMENTATION Division of Plan Responsibilities Institutional Requirements SUMMARY OF COMPLIANCE AND PUBLIC INVOLVEMENT* Environmental Laws and Regulations Public Involvement RECOMMENDATION FINDING OF NO SIGNIFICANT IMPACT LITERATURE CITED ii

9 FIGURES Figure ES-1. Location of McGregor Lake HREP Project Area... ES-II Figure ES-2. McGregor Lake HREP Recommended Plan... ES-III Figure 1. McGregor Lake HREP Project Area... 3 Figure 2. Cut at Northeast Corner of McGregor Lake, Looking East Towards the East Channel. 13 Figure 3. Cut Forming in Southwest Section of McGregor Lake, Looking East Towards the Lake Figure 4. WDNR McGregor Lake Water Quality Sample Sites Figure 5. Tree Species Relative Abundance from Forest Inventory for the Project Area Figure 6. Location of the East Channel Essential Habitat Area for Higgins eye Mussel in Blue 23 Outline Figure 7. Changes in Cover Type for the Project Area from Figure 8. Average Annual Discharge at the McGregor, Iowa USGS Gage from 1938 to Figure 9. Cost Effectiveness Analysis of All Alternatives Figure 10. Best Buy Plans Incremental Cost and Output Results Figure 11. McGregor Lake HREP Recommended Plan Figure 12. Rusty Patched Bumble Bee Potential Zones...65 Figure 13. Rusty Patched Bumble Bee High Potential Zones Figure 14. Environmental Justice Mapping Tool TABLES Table 1. Water Depth in McGregor Lake... 9 Table 2. Stage-Discharge Data McGregor Lake Table 3. Control Conditions at Lock and Dam No Table 4. Seasonal Water Surface Elevation for Project Area (50% Duration) Table 5. Water Quality Data for Pool 9 in Comparison to Established Guidelines Table 6. Cover Type Acreage by Year for the Project Area Table 7. Species Listed Under the Federal Endangered Species Act Within or Near the Project Area Table 8. State-Listed Threatened and Endangered Species Not Federally Listed...25 Table 9. County and State Population Trend Table 10. Per Capita Income and Poverty Rate by County/State (2010) Table 11. Phase 1 Measures That Form the Basis for Alternative Formulation...45 Alternative Formulation Table 12. Project Features for the McGregor Lake HREP Study that Will Be Carried...45 Forward and Included with Project Alternatives Table 13. Alternative Combinations for the McGregor Lake HREP Study Carried Forward for Detailed Analysis Table 14. Habitat Benefits by Habitat Type for Each Alternative Table 15. Costs, Benefits, and Cost per Habitat Unit for All Alternatives Table 16. Results of CE/ICA for Best Buy Plans Table 17. Environmental Assessment Matrix for Proposed Project Table 18. CEQ s Approach for Assessing Cumulative Effects Table 19. Past, existing, and potential future Habitat Restoration and Enhancement Projects in Pool 10 Table 20. Estimated Quantities and Footprints of Material for the Recommended Plan Table 21. Maintenance, Repair, Replacement & Rehabilitation Cost Categorization of Project Features iii

10 Table 22. Project First Costs for Design & Construction of Recommended Plan Table 23. Average Annual Costs for Recommended Plan* Table 24. Estimated Project Schedule Table 25. Compliance Review with All Applicable Environmental Regulations and Guidelines. 84 APPENDICES Appendix A Correspondence Appendix B Clean Water Act Compliance Appendix C Memorandum of Agreement Appendix D Habitat Evaluation Procedures Appendix F Sediment Report Appendix G Geotechnical Analysis Appendix H Hydrology and Hydraulics Appendix I Cost Engineering Appendix J Real Estate Plan Appendix K 2014 Problem Appraisal Report Appendix M Value Engineering Study Appendix N Plates Plate 1 Project Area Plate s Landcover Plate Landcover Plate Landcover Plate Landcover Plate Landcover Plate s Aerial Photo Plate 8 Bathymetry Plate 9 Topography Plate 10 Overwintering Sites Plate 11 Bald Eagle Nests Plate 12 Project Features Plate 13 Recommended Plan Appendix O Plan Formulation and Alternative Analysis Appendix P Monitoring and Adaptive Management Appendix Q Distribution List Appendix R Civil Engineering iv

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12 FEASIBILITY REPORT AND INTEGRATED ENVIRONMENTAL ASSESSMENT MCGREGOR LAKE HABITAT REHABILITATION AND ENHANCEMENT PROJECT POOL 10, UPPER MISSISSIPPI RIVER CRAWFORD COUNTY, WISCONSIN 1. INTRODUCTION 1.1. AUTHORITY Congress first authorized the Upper Mississippi River Restoration program (UMRR) in Section 1103 of the 1986 Water Resources Development Act of 1986 (WRDA 1986) (Public Law ), codified at 33 U.S.C Over the course of its first 13 years, the UMRR program proved to be one of this country s premier ecosystem restoration programs, combining close collaboration between Federal and State partners, an effective planning process, and a built-in monitoring process. This success led Congress to reauthorize the UMRR program in the Water Resources Development Act of 1999 (WRDA 1999) (Public Law ). Section 509 of the WRDA 1999 made several adjustments to the program and established the following two elements as continuing authorities: Planning, construction, and evaluation of fish and wildlife habitat rehabilitation and enhancement projects (HREPs). Long-term resource monitoring, computerized data inventory and analysis, and applied research (known collectively as Long-Term Resource Monitoring element (LTRM). The proposed planning and design of the McGregor Lake HREP, as well as construction, would be funded under this authorization PARTICIPANTS AND COORDINATION Participants in the planning for the McGregor Lake HREP included the Upper Mississippi River (UMR) National Wildlife and Fish Refuge (Refuge) and the Region 3 Offices of the U.S. Fish and Wildlife Service (USFWS), the Wisconsin and Iowa Departments of Natural Resources (WDNR and IDNR), and the U.S. Army Corps of Engineers, St. Paul District (Corps). The USFWS, the WDNR, and the IDNR were involved in project planning because the project area is located within the Refuge and is located within the portion of Pool 10 bounded by Wisconsin and Iowa. The USFWS is considered a cooperating agency under Federal regulations governing the implementation of the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C et seq. 1

13 The following agencies played an active role in the planning of the McGregor Lake project. For the St. Paul District, Project Delivery Team disciplines are listed. For resource agency personnel, the individual s position title is listed. U.S. ARMY CORPS OF ENGINEERS Program Management Geotechnical Archaeologist and Tribal Liaison Project Management Real Estate Channel Maintenance Planning Cost Engineer Cartographer/GIS Biologist Construction Engineer Hydraulic Engineer Civil Engineer U.S. FISH AND WILDLIFE SERVICE, UPPER MISSISSIPPI NATIONAL WILDLIFE AND FISH REFUGE Deputy Refuge Manager, Upper Mississippi National Wildlife and Fish Refuge Wildlife Biologist, Upper Mississippi National Wildlife and Fish Refuge Environmental Engineer, Upper Mississippi National Wildlife and Fish Refuge McGregor District Manager, Upper Mississippi National Wildlife and Fish Refuge Deputy McGregor District Manager, Upper Mississippi National Wildlife and Fish Refuge Wildlife Biologist, McGregor District, Upper Mississippi National Wildlife and Fish Refuge Fishery Biologist, La Crosse Fish and Wildlife Conservation Office Fish and Wildlife Biologist, Minnesota/Wisconsin Field Office Regional Historic Preservation Officer/Archaeologist, Regional Office WISCONSIN DEPARTMENT OF NATURAL RESOURCES Fisheries Technician Fisheries Biologist Mississippi River Wildlife Biologist Mississippi River Water Quality Specialist IOWA DEPARTMENT OF NATURAL RESOURCES Habitat Projects Coordinator Natural Resources Biologist Fisheries Biologist 1.3. PURPOSE The vision of the UMRR Program is: A Healthier and More Resilient Upper Mississippi River Ecosystem that Sustains the River's Multiple Uses. The mission of the UMRR program is to work within a partnership among Federal and State agencies and other organizations; to construct high-performing habitat restoration, rehabilitation projects; to produce state-of-theart knowledge through monitoring, research, and assessment; to engage other organizations to accomplish the UMRR Program's vision. Within this program mission, the purpose of this HREP Project is to rehabilitate, enhance, and maintain diverse riverine and floodplain habitat for fish and wildlife. This specific project purpose is to improve floodplain forest, backwater fisheries, and emergent wetland habitat in Pool 10 of the UMR. The purpose of this Feasibility Report and Integrated Environmental Assessment (EA), including the Finding of No Significant Impact (FONSI), is to evaluate the proposed project within the UMRR program. The Feasibility Report and Integrated EA meets Corps of Engineers 2

14 planning guidance and NEPA requirements. This report is developed by the Corps with the USFWS serving as the Federal project partner. This report provides planning, engineering, and sufficient construction details of the Recommended Plan to allow final design and construction to proceed subsequent to document approval. The purpose of the main report is to summarize the multidisciplinary efforts of the Corps, USFWS, WDNR, and the IDNR that led to the study recommendation. The report is organized to follow a general problem-solving format; existing conditions and anticipated future conditions are reviewed; project goals and objectives are identified; restoration alternatives are formulated to address the goals and objectives; costs and benefits of the restoration alternatives are identified and the alternatives are compared on this basis; a single restoration plan is recommended for implementation (the Recommended Plan); and a detailed analysis on the plan is presented. The detailed analysis includes design and construction considerations; operations and maintenance considerations; a detailed cost estimate; a plan for monitoring the performance of the restoration; real estate requirements; environmental effects; and a detailed schedule for implementation. Appendices are provided as supporting documentation PROJECT AREA The project area is located on the Wisconsin side of the UMR in Pool 10. The project area includes the 200 acre McGregor Lake and the adjacent terrestrial floodplain and secondary channels that make up the island complex between the main and east channels (Figure 1; Plate 1). The entire project area lies within the Refuge. Figure 1. McGregor Lake HREP Project Area 1.5. RESOURCE SIGNIFICANCE Engineering Regulation , The Planning Guidance Notebook (2000), defines resource significance in terms of institutional, public, and technical recognition. Resource significance means that some entity, law/policy/regulation, or scientific evidence indicates that a particular resource is important. Institutional Recognition: Institutional recognition means that the importance of an environmental resource is acknowledged in the laws, adopted plans, and other policy statements of public agencies, tribes, or private groups. Sources of institutional recognition include public laws, executive orders, rules and regulations, treaties, and other policy statements of the Federal Government; plans, laws, resolutions, and other policy statements of states with jurisdiction in 3

15 the planning area; laws, plans, codes, ordinances, and other policy statements of regional and local public entities with jurisdiction in the planning area; and charters, bylaws, and other policy statements of private groups. Public Recognition: Public recognition means that some segment of the general public recognizes the importance of an environmental resource, as evidenced by people engaged in activities that reflect an interest or concern for that particular resource. Such activities may involve membership in an organization, financial contributions to resource-related efforts, and providing volunteer labor and correspondence regarding the importance of the resource. Technical Recognition: Technical recognition means that the resource qualifies as significant based on its technical merits, which are based on scientific knowledge or judgment of critical resource characteristics. Whether a resource is determined to be significant may of course vary based on differences across geographical areas and spatial scale. While technical significance of a resource may depend on whether a local, regional, or national perspective is undertaken, typically a watershed or larger context should be considered. Technical significance should be described in terms of one or more of the following criteria or concepts: scarcity, representativeness, status and trends, connectivity, limiting habitat, and biodiversity. Scarcity is a measure of a resource s relative abundance within a specified geographic range. Generally, scientists consider a habitat or ecosystem to be rare if it occupies a narrow geographic range (i.e. limited to a few locations) or occurs in small groupings. Unique resources, unlike any others found within a specified range, may also be considered significant, as well as resources that are threatened by interference from both human and natural causes. Representativeness is a measure of a resource s ability to exemplify the natural habitat or ecosystem within a specified range. The presence of a large number and percentage of native species, and the absence of exotic species, implies representation as does the presence of undisturbed habitat. Status and Trend measures the relationship between previous, current and future conditions. Connectivity is the measure of the potential for movement and dispersal of species throughout a given area or ecosystem. Limiting Habitat is habitat that is essential for the conservation, survival, or recovery of one or more species. Biodiversity is a measure of the variety of distinct species and the genetic variability within them. The following documents the resource significance specific to the McGregor Lake HREP. Institutional Recognition: Habitats of the UMR have been recognized as a significant resource by a number of public agencies and other institutions. The Izaak Walton League and a number of other organizations recognized the importance of the UMR and convinced Congress to preserve a large section of the floodplain in 1924 through the acquisition of land and formation of a refuge for wildlife and fish (later became the Upper Mississippi River National Wildlife and Fish Refuge). In 1986, U.S. Congress designated the UMR System (UMRS) as both a nationally significant ecosystem and a nationally significant commercial navigation system in Section 1103 of the WRDA The Upper Mississippi River Floodplain Wetlands are designated as a Ramsar Wetland of International Importance as well as a Globally Important Bird Area. The National Research Council s Committee on Restoration of Aquatic Ecosystems targeted the UMR for restoration as one of only three large river-floodplain ecosystems so designated. The Upper Mississippi River Basin Association is an advocate for restoration of habitat on the UMR. In addition, the Upper Mississippi River Conservation Committee (UMRCC) recognized the importance of the floodplain forest, fish, and wildlife of the river. Institutional recognition of significant fish and wildlife resources is also documented through the following laws and regulations: National Wildlife Refuge System Administration Act of 1966 and the National Wildlife Refuge System Improvement Act of

16 Clean Water Act, 33 U.S.C et seq. Fish and Wildlife Conservation Act of 1980, 16 U.S.C et seq. Fish and Wildlife Coordination Act, 16 U.S.C. 661 et seq. National Wildlife Refuge System s Biological Integrity, Diversity, and Environmental Health Policy, 601 FW 3. Public Recognition: The public recognizes the UMR, including Pool 10, as a nationally, regionally, and locally significant resource. Some of the public services the Mississippi River provides include aesthetics, recreation, science, education, history, raw materials, and flood regulation. In general, the services identified show the wide range of uses from the river, which extend beyond the ecological health of the UMR, and directly relate to public welfare and longterm ecological health of the region. American Rivers, a non-governmental organization dedicated to protecting and restoring healthy, natural rivers, listed the Mississippi River in America s Top Ten Endangered Rivers for The River was a special mention on the 2011 list. Technical Recognition: Numerous scientific analyses and long-term evaluations of the UMR have documented its significant ecological resources. Since the early 1900s, researchers, government agencies, and private groups have studied the larger river system and proposed ecosystem restoration in the UMR. The Federal and state natural resource specialists that work in the project area have also identified areas in need of habitat restoration (Theiling et al. 2000). Resource agencies view the resources in Pool 10 as significant, as reflected by the ongoing restoration and enhancement efforts in the pool, including the proposed Lower Pool 10 HREP. Additionally, the Environmental Pool Plan for Pools 1-10 documents the desired future habitat conditions for Pool 10, which includes improving terrestrial habitat by increasing the quality and diversity of floodplain forest, along with improvements to aquatic habitat. Representativeness and Scarcity: The McGregor Lake project area is host to many of the flora and fauna found in the UMR and currently contains about 370 acres of floodplain forest habitat. Although limited, the area does contains scattered stands of hard mast trees, swamp white oak in particular. This a rare forest type in the UMR, and the remaining oak forest has become more fragmented due to changed conditions. Limiting Habitat and Connectivity: Floodplain forest communities in the project area have changed dramatically since European settlement and construction and operation of the locks and dams, with a declining trend in diversity and connectivity of large contiguous forests. The decline and fragmentation of diverse forests have impacted the connectivity of the UMR flyway for migratory songbirds. Furthermore, sedimentation and increased flow to backwaters have caused a decline in backwater overwintering habitat within the UMR. These factors negatively affect the overall structure and health of the UMR. The McGregor Lake HREP has the potential to reverse the declining trends and improve habitat within the project area DECISIONS TO BE MADE U.S. ARMY CORPS OF ENGINEERS Because the proposed project is funded by the Corps, the St. Paul District Commander will select one of the alternatives for implementation. The District Commander will also determine, based on the facts and recommendations contained herein, whether the EA is adequate to support a FONSI or whether an Environmental Impact Statement (EIS) will be prepared. The Mississippi Valley Division (MVD) Commander has the final approval of the Feasibility Report and the recommended plan. 5

17 U.S. FISH AND WILDLIFE SERVICE Because the project would be located on land managed by the Refuge, the Regional Director of the USFWS, Region 3, will determine whether the project is compatible with Refuge goals and objectives, the Refuge Comprehensive Conservation Plan (2006), and the Refuge Habitat Management Plan (Draft 2018). The USFWS Regional Director will also determine if the USFWS approves the selected alternative for potential implementation and if the USFWS will assume operation and maintenance responsibilities. The Regional Director will also determine, based on the facts and recommendations contained herein, whether the final integrated Feasibility Report and EA meets the USFWS s obligation under the following: National Wildlife Refuge System Administration Act of 1966 National Wildlife Refuge System Improvement Act of 1997 NEPA Fish and Wildlife Coordination Act Endangered Species Act of 1973 Migratory Bird Treaty Act of 1918 Bald and Golden Eagle Protection Act of The USFWS has been a cooperating agency and integral in the decision making process for the Feasibility Report. Before any work is commenced under a construction contract, the Corps will obtain a Special Use Permit from the Refuge Manager. This permit will be included in the technical specification package and be part of the contract documents. STATES Decisions to be made by the State of Wisconsin include permits for dredging, disposal and structures, and archeological review. This project would require endorsement by the River Resources Forum (RRF). The RRF is a state and Federal agency partnership for addressing resource issues concerning the UMRS within the St. Paul District s geographic jurisdiction. The States of Wisconsin and Iowa have been partnering agencies and integral in the decision making process for the Feasibility Report SELECTION PROCESS ELIGIBILITY CRITERIA In January 1986, prior to enactment of Section 1103 of WRDA 1986, the U.S. Army Corps of Engineers, North Central Division, completed a General Plan for implementation of the UMRR Program (formerly named the Upper Mississippi River System Environmental Management Program, or UMRS-EMP). The USFWS, Region 3, and the five affected States (Illinois, Iowa, Minnesota, Missouri, and Wisconsin) participated through the Upper Mississippi River Basin Association. Programmatic updates of the General Plan for budget planning and policy development are accomplished through Annual Addenda. Coordination with the States and USFWS during the preparation of the General Plan and Annual Addenda led to an examination of the Comprehensive Master Plan for the Management of the UMRS. The Master Plan, completed by the Upper Mississippi River Basin Commission in 1981, was the basis for the recommendations enacted into law in Section The Master Plan and General Plan reports identified examples of potential habitat rehabilitation and enhancement techniques. Consideration of the Federal interest and Federal policies has resulted in the conclusions below: 6

18 a. From the First Annual Addendum: The Master Plan report and the authorizing legislation do not pose explicit constraints on the kinds of projects to be implemented under UMRS-EMP. For habitat projects, the main eligibility criterion should be that a direct relationship should exist between the project and the central problem as defined by the Master Plan; i.e., the sedimentation of backwaters and side channels of the UMRS. Other criteria include geographic proximity to the river (for erosion control), other agency missions, and whether the condition is the result of deferred maintenance b. From the Second Annual Addendum. (1) The types of projects that are definitely within the realm of Corps of Engineers implementation authorities include the following: backwater dredging dike and levee construction island construction bank stabilization side channel openings/closures wing and closing dam modifications aeration and water control systems waterfowl nesting cover (as a complement to one of the other project types) acquisition of wildlife lands (2) A number of innovative structural and nonstructural solutions, which address human-induced impacts, particularly those related to navigation traffic and operation and maintenance of the navigation system, could result in significant long-term protection of UMRS habitat. Therefore, proposed projects that include such measures will not be categorically excluded from consideration, but the policy and technical feasibility of each of these measures will be investigated on a case-by-case basis and the measures will be recommended only after consideration of system-wide effects. PROJECT SELECTION Projects are nominated for inclusion in the St. Paul District s habitat restoration program by a State natural resource agency or the USFWS, based on agency management objectives. To assist the District in the selection process, the States and the USFWS have agreed to use the expertise of the Fish and Wildlife Work Group (FWWG) of the RRF to consider critical habitat needs along the Mississippi River and sequence nominated projects on a biological basis. The FWWG consists of river managers responsible for managing the river for their respective agencies. Meetings are held on a regular basis to evaluate and rank nominated projects according to the biological benefits they could provide in relation to the habitat needs of the river system. The ranking is forwarded to the RRF for consideration of the broader policy perspectives of the agencies involved. The RRF submits the coordinated ranking to the District and each agency officially notifies the District of its views on the ranking. The District then formulates and submits a project that is consistent with the overall program guidance as described in the UMRR General Plan and Annual Addenda and supplemental guidance provided by the MVD. Personnel familiar with the river have screened the potential projects. Resource needs and deficiencies have been considered on a pool-by-pool basis to ensure that regional needs are being met and that the best expertise available is being used to optimize the habitat benefits created at the most suitable locations. 7

19 The McGregor Lake HREP was identified for consideration by the WDNR and evaluated in 2008 by the FWWG for consideration in the St. Paul District s habitat projects program. In 2010, the project fact sheet was approved by MVD. A Problem Appraisal Report was completed on McGregor in 2014, establishing the goals and objectives for the area, as well as the planning considerations for the feasibility study. The feasibility study for this project was initiated in 2016, in partnership with the U.S. Fish and Wildlife Service, and the Iowa and Wisconsin DNRs. During the planning phase, the agency partners agreed to focus primarily on development and establishment of floodplain forest habitat measures at McGregor Lake. 2. ASSESSMENT OF EXISTING RESOURCES Chapter 2 assesses the existing conditions of resources, organized by resource topic, within Pool 10 of the UMR and the project area. Resource topics analyzed in detail include natural resources (floodplain habitat, riverine, geology and soils, fish and wildlife, Wisconsin resources of concern, federally-listed species, migratory birds, invasive species, water quality, and air quality); hazardous, toxic and radioactive waste; historical and cultural resources; socioeconomic resources; aesthetic resources; climate change; and noise levels. This is not a comprehensive discussion of every resource within the project area, but rather focuses on those aspects of the environment that were identified as relevant issues during scoping or that may be affected by the alternatives considered. The environmental consequences to these resources that are likely to result from the construction of project features are described in Chapter PHYSICAL SETTING Pool 10 is part of the 9-foot channel project on the UMR and was created in 1937 by the construction of Lock and Dam 10. The entire pool extends almost 33 miles (river mile to 647.9). The project pool elevation is feet (NAVD 1988), which creates a pool surface area of 17,070 acres and approximately miles of meandering shoreline (USACE 2011). Wisconsin is located on the left descending riverbank and Iowa is on the right riverbank. The pool s valley ranges in width from about 1.25 miles to over 3 miles where the Wisconsin River flows into Pool 10 at Prairie du Chien, WI. The Wisconsin River enters Pool 10 less than two miles downstream of the project area, forming a large delta. While sediment from the Wisconsin River doesn t directly affect the project area, there are two physical effects that do influence the project area. First, longitudinal gradient flattening in the UMR reach upstream of the confluence with the Wisconsin River appear to be related to the effects of the Wisconsin River alluvial fan (USACE, 2000). Second, flow variation on the Wisconsin River can influence water levels in the project area increasing short-term water level variation. The majority of the pool includes a mix of habitats including main channel, side channels and island habitat. The Pool 10 floodplain includes nearly 39,900 acres, of which about 11,600 acres is wet floodplain forest and meadow, 4,000 acres is submerged and floating leaf vegetation, 3,600 acres is emergent marsh, and 11,300 acres is open water (Theiling et al., 2000). The project area is 1,063 acres that extends three miles, from river mile to It is bounded by East Channel to the south and east and by the main channel on the west (Plate 1). U.S. Highway 18 bisects the project area via the Marquette-Joliet Bridge, running west and east from Marquette, IA to Prairie du Chien, WI. On the north side of the highway, a channel called Sturgeon Slough runs from the East Channel south to the highway, where it flows under the highway and rejoins the main channel. Floodplain forest, emergent marsh, and shallow backwater ponds form a mosaic of habitat around the slough. The northern tip of the island was protected from erosion through an HREP in South of the highway, a channel called Lovers Lane flows east along the highway embankment before turning south, making two sinuous 8

20 turns, and then rejoining the main channel at the south end of the project area. A small channel called Honeymoon Slough cuts from the main channel into Lovers Lane at the southern end of the Slough. South of the highway there are several high ridges with a diversity of tree species, including swamp white oak and bitternut hickory. Emergent marshes of rushes, sedges, and cattails are found in several locations. McGregor Lake is approximately 200 acres, and has very little aquatic vegetation BATHYMETRY McGregor Lake (200 acres) has an average depth of 2 to 3 feet (range 0-4 feet) under typical low flow conditions (75% exceedance, which is NAVD 88), which includes the winter season (Plate 8). Sedimentation may have decreased depth, with maximum depths limited to only small pockets with 3 to 4 feet (less than 8% of total lake area). Most of McGregor Lake has depths of three feet or less. Almost 55% of the lake is less than 2 feet deep (Table 1). Although affected by sediment deposition, McGregor Lake is located in a reach of the UMR with a low sediment load. However, McGregor Lake is becoming more connected to the East Channel through a cut in the northeast corner of the lake. As this cut widens and deepens, sedimentation will increase. Plate 8 shows the most recent bathymetry data for the lake, collected by Corps staff in There is little additional historical data available for project area bathymetry. Table 1. Water Depth in McGregor Lake. Water Depth Categories (feet) Relative % of Lake Area <1 21.0% % % % 4 + 0% 2.3. AQUATIC AND TERRESTRIAL HABITAT Pool 10 has a high variety of terrestrial and aquatic habitat conditions that change in diversity, complexity and quality between the different areas of the pool. From a pool-wide perspective, these habitats continue to support a diverse and productive fishery and provide important terrestrial and wetland habitat. However, the habitat quality for certain habitat types, especially floodplain forest and overwintering fish habitat, is often of poor quality across many areas of the UMR, including Pool 10. Aquatic habitat in Pool 10 includes a mix of main channel, channel border, secondary channels, backwater lakes, impounded area, and tail water. Terrestrial habitat is predominately bottomland forest. The important characteristics of these habitat types, relative to fish and wildlife uses, are described in Sections and AQUATIC HABITAT Pool 10 contains main channel habitat where the majority of river discharge occurs and includes the navigation channel. This is the deepest part of the channel, which lacks rooted vegetation and varies in velocity with water stages. Sediments are usually dominated by sand. Between the navigation channel and the riverbank is the channel border. The quality of habitat in some sections of the channel border has been degraded due to sedimentation, historic dredged material placement and effects of channel training structures. Secondary channels, shallow backwater lakes, navigation channel and channel border areas, and broad secondary channels form a dynamic mosaic of aquatic habitat in the project area. McGregor Lake is the main water feature of the project area and includes about 200 acres of river backwater habitat. McGregor Lake and backwater wetlands in the project area support 9

21 submerged and floating macrophytes such as pondweeds, wild celery, and American lotus providing habitat for many fish and wildlife species. Sturgeon Slough is the 400-acre complex of running secondary channels, shallow backwater, and floodplain forest in the northern half of the project area upstream of U.S. Highway 18 (Plate 1). The project area is bounded on both sides by the main channel and the east channel. The main channel area includes representative main channel and channel border habitats. The East Channel is essentially a secondary channel of the UMR (Wilcox 1993). The upstream portion of the East Channel is characteristic of navigation channel and channel border aquatic areas: navigated by commercial traffic, 9-foot minimum depths in the navigation channel, sand/siltysand substrates, continuous currents and limited rooted aquatic vegetation. The combination of depths, sediment types and current velocities makes the East Channel quality habitat for freshwater mussels. Limited commercial navigation traffic occurs within the East Channel. TERRESTRIAL HABITAT Terrestrial habitats within the floodplain of Pool 10 include areas of forest, brush and wet shrub, wet meadows, areas disturbed by commercial or residential development and agricultural land. Forested areas in the region are of two types: upland forests on the bluff slopes adjacent to the floodplain and wet forests of the floodplain. Within Pool 10 there were about 10,000 acres of floodplain forest in Based on U.S. Geological Survey (USGS) landcover data, wet meadows cover nearly 600 acres of the floodplain in Pool 10, and willows/shrubs cover just over 90 acres. These habitat types are very important to a variety of wildlife and showed significant declines in acreage when the pool was inundated. Much of these cover types were converted to deep and shallow marshes as well as large contiguous open water areas above the lock and dam. This conversion to aquatic habitat wasn t as significant a factor at the project area due to the fact that it is 18 miles upstream of the lock and dam and above the control point for Pool 10. However there was a slight upward shift in water surface elevations that is described in more detail in Section Developed areas (including roads and levees) are prevalent in the floodplain of Pool 10 with over 5,100 acres. Nearly half of the developed area lies in the community of Prairie du Chien, WI, just east of the project area. Agricultural lands (approximately 2,100 acres) include areas devoted to the production of annual crops, pastures, or landscape nurseries. The land within the project area has significant variation in topography, rising up to 8 feet (elevation 620) above the low flow pool elevation (elevation 612). Terrestrial habitat within the project area is predominantly floodplain forest, and like much of the Pool 10 floodplain forest, is dominated by silver maple WATER RESOURCES UPPER MISSISSIPPI RIVER POOL 10 The gage at Lock & Dam (LD) 9 was used for hydrology data for the project area because the gage at LD 10 is highly influenced by the Wisconsin River, which enters the Mississippi River downstream of the project area. LD 9 more closely approximates the hydrology at the project area than LD 10. Early summer (June) discharges at LD 9 generally range from 30,000 to 60,000 cubic feet per second (cfs). By late summer, discharges usually decrease to a range of 20,000 to 40,000 cfs. Winter low flows are usually in the range of 15,000 to 25,000 cfs. Table 2 shows the discharges and stages at McGregor Lake associated with the various flow events. A datum conversion of feet was used to convert elevations from mean sea level (MSL) 1912 to NAVD

22 Table 2. Stage-Discharge Data McGregor Lake. Annual Chance Description of Flood 2 Flow Condition McGregor gage Water Surface Elevation (NAVD 1988), RM Discharge (cfs) % of Time Exceeded 1 28, Low flow , Moderate flow , , Bankfull Events , , Small floods 140, ,000-1 Large flood Discharge duration information is based on discharge data at LD Discharge frequency data is based on the 2004 Flow Frequency Study. 3 LD 10 operating curves. Following lock and dam construction in 1937, Pool 10 was filled in April The project pool elevation was and still is feet MSL 1912 adjusted ( ft NAVD 1988). During the first 8 years of operation, the allowable drawdown at the dam during the growing season was 2.0 feet to elevation ( ft NAVD 1988). In 1971, operation was changed so the maximum drawdown at LD 10 is 1.0 foot to elevation ( FT NAVD 1988) Table 3 describes the river discharge for these different control conditions, including the resulting water elevations at LD 10, as well as Clayton Iowa at approximately River Mile 625. As river discharge rises and falls, control conditions are shifted which impacts water elevations throughout the pool. Table 3. Control Conditions at Lock and Dam No. 10. Control Conditions Approximate Discharge Clayton Gage Elev. (NAVD 1988) LD 10 Pool Elev. (NAVD 1988) Primary < 42,000 cfs ft ft Secondary 42,000 to 52,000 cfs ft < ft > ft Tertiary 52,000 to 78,000 cfs > ft ft Open-River > 78,000 cfs > ft > ft The project area is over 18 miles upstream of LD 10 and is upstream of the Wisconsin River, which is a major tributary and geomorphic control in this reach of the UMR. Because of its significant distance from the downstream dam, there is significant variation in water surface elevation and during the growing season, water surface elevations in this area are fluctuating between and Stage information for the water surface elevation exceeded 50% of the time (annually and monthly) is shown is provided in Table 4. 11

23 Table 4. Seasonal Water Surface Elevation for Project Area (50% Duration). Month McGregor (ft, NAVD1988) LD 10 (ft, NAVD 1988) All Year January February March April May June July August September October November December Water surface variation affects habitat conditions in the project area a number of ways. The increased water depths associated with LD operation created aquatic habitat where previously it did not exist, though this effect was limited in the project area further upstream, compared to downstream areas closer to navigation dams. While pool regulation creates a minimum water surface elevation below which inundation is permanent, in this case elevation (NAVD 1988), this reach of the river still retains some of its pre- lock and dam riverine character TRIBUTARIES The Wisconsin River is a major tributary that enters the floodplain approximately two miles south of the project area, forming the Wisconsin River Delta. The Wisconsin River contributes approximately 20% of river flow to the UMR at their confluence. It has a large influence on hydrology and sediment transport for areas immediately adjacent to and downstream of the project area. The Wisconsin River also is important for biological transport in terms of fish species that move back and forth between the Wisconsin and Mississippi rivers to meet different seasonal needs. Land use/land cover in the watershed of this tributary is a mix of agriculture in the southern watershed, with more forest habitat in the headwaters of northern Wisconsin. Several major reservoirs also influence hydrology and sediment transport on the Wisconsin River GROUNDWATER Large quantities of groundwater are present in the highly permeable, surficial sand deposits. The principle aquifer for shallow wells (less than 150 feet) is the Franconia formation. Deeper wells in the northern end of the Pool 10 region may penetrate into the Galesville or Eau Claire formation, although water quality would not differ much from that of the Franconia formation. Groundwater is considerably harder than the UMR in Pool 10. Analysis by the WDNR shows that groundwater is not a significant influence in the project area FLOW AND CURRENT VELOCITY Even though impoundment has altered conditions in Pool 10, the project area still retains riverine characteristics more commonly found in the upper ends of navigation pools. Hydraulic connectivity between the project area and the adjacent channels is relatively low and is seasonal 12

24 (i.e. connectivity increases in the spring when flow rates are high). However, there are some parts of the project that are too connected and therefore have too much flow in the winter to function as high quality overwintering habitat At the northeast corner of McGregor Lake, a cut has formed that connects the lake with the East Channel. This cut is approximately 10 feet wide with a bottom elevation of 612, as shown in Figure 2. The cut is anticipated to increase in size via widening and downcutting during high flows. Under existing conditions, McGregor Lake has negligible current velocities under all but the highest flow conditions when the floodplain is inundated with flood waters. However, this could change substantially if the East Channel breaks into McGregor Lake in the future. If the connection expands, this will allow cold, flowing water to enter McGregor Lake during winter conditions, degrading the area s value for overwintering. The connection would also increase sedimentation in the lake. There is also a cut forming in the southwest corner of the lake from Honeymoon Slough, as shown in Figure 3. The trees along the thin natural levee have been almost completely lost to erosion. The velocity in Honeymoon Slough is relatively high, and this cut is expected to increase in size, introducing more cold water in the southern portion of the lake and reducing overwintering value. Figure 2. Cut at Northeast Corner of McGregor Lake, Looking East Towards the East Channel. Figure 3. Cut Forming in Southwest Section of McGregor Lake, Looking East Towards McGregor Lake. 13

25 2.8. WIND AND WAVE ACTION Wind generated waves reduce the ability of aquatic vegetation to grow in some areas by exerting a physical force on the vegetation and suspending sediment in water, leading to increased turbidity and reduced light penetration. McGregor Lake appears to be relatively protected from large wind fetches but may be vulnerable to winds from the south-southwest due to the orientation of the lake opening to the main channel. Wind data from the Prairie du Chien, WI airport and Pool 10 bathymetry are available and were used to assess potential wind fetch and sediment resuspension. The prevailing winds during the growing season blow from the southeast to the northwest, which crosses the shorter transect of the lake WATER QUALITY Mead (1995), in investigations of contaminants in the UMR from 1987 to 1992, found water quality to be generally better in this reach of the river than above Lake Pepin and in the reach downstream where tributaries that drain the Corn Belt begin to enter the UMR. In 2004, 2007, 2014, 2016, and 2017 the WDNR and in 2014, the Corps of Engineers collected winter dissolved oxygen (DO), temperature and velocity readings from McGregor Lake at multiple locations. Figure 4 shows the approximate WDNR sample sites. Results from these three years suggest that under normal ice cover conditions, the deepest portion of McGregor Lake (3-4ft during the winter) has a stratified water column due to a temperature gradient. The majority of the lake is much shallower (2 ft or less) and not stratified. Water temperatures within McGregor Lake were typically between 2 and 4 C, though some lower temperatures were observed, especially near the ice surface. Velocity measurements demonstrate there is very little or undetected water movement in McGregor Lake. DO readings were often between 3 and 5 mg per liter (mg/l), but periods of extremely low DO (e.g., 2 mg/l or less) were observed, with a minimum of 0.5 mg/l observed in Stagnant water combined with a sediment oxygen demand and shallow depths are probably the main drivers of low DO during the winter. DO levels near the sediment surface rarely exceed the guideline of 5 mg/l for most freshwater fisheries. Secondary channels and off-channel aquatic habitat outside of McGregor Lake had more variable winter water quality conditions. Water temperatures in these areas were below 2 C, and also tended to have higher levels of DO, compared to McGregor Lake. This is most likely due to a greater level of connection to the river, which results in greater water velocities, greater mixing of water, and infusion of fresh water from the main channel. 14

26 Figure 4. WDNR McGregor Lake Water Quality Sample Sites. During the rest of the year, the water quality conditions for the project area are not clear due to a lack of data. In general, however, an assessment of selected parameters of water quality data in Pool 9 suggests upper Pool 10 water quality conditions are fair. Pool 9 is a better approximation of water quality at the project site given that much of Pool 10 is highly influenced by the Wisconsin River immediately downstream (Table 5). Data collected since 1977 were obtained from the WDNR and summarized for selected parameters in comparison to recommended guidelines recognized by UMRR s Long Term Resource Monitoring Program (LTRMP). Except for isolated secondary channels and backwater lakes, the DO content of the water remains high year round and above levels required to sustain a quality fishery. Turbidity and phosphorus levels are higher than desired. Turbidity affects fish and other aquatic organisms by reducing 15

27 flood supplies, degrading spawning beds, and affecting gill function (MCPA, 2008). High phosphorus levels are especially problematic when sediment-bound phosphorus settles into backwaters and feeds algal blooms and duckweeds, reducing light availability to other aquatic vegetation and reducing oxygen supply (Houser and Richardson, 2010). Nitrogen levels are slightly higher than the guidelines, but lower than the chronic nitrate standard currently under consideration by the State of Minnesota, which requires that the 4-day average concentration of nitrate-n not exceed 4.9 mg/l more than once in a 3-year period (MPCA, 2010). Minnesota standards were used because Wisconsin and Iowa have not published water quality standards for nitrogen in surface waters. Table 5. Water Quality Data for Pool 9 in Comparison to Established Guidelines. Levels in Pool 9 are likely similar to that for upper Pool 10 upstream of the confluence with the Wisconsin River. Total Phosphorous (mg/l) Chlorophyll a (µg/l) Total Nitrogen (mg/l) Summer Total Suspended Solids (mg/l) Dissolved Oxygen (mg/l) Guidelines a b a <25 c >5.0 d Pool 9 e Mean Pool 9 e Range a Source of procedures described for determining this: USEPA 2000; Smith et al b Source: Dodds et al c Source: summer average; Upper Mississippi River Conservation Committee d Source: Upper Mississippi River Basin Association e Source: WDNR water quality data; (Attachment 12). GEOLOGY AND SOIL/SUBSTRATE The most significant geologic event explaining the nature of the UMR within Pool 10 occurred at the end of the Pleistocene glaciation approximately 10,000 years ago. Tremendous volumes of glacial meltwater, primarily from the Red River Valley's glacial Lake Agassiz, eroded the Minnesota and Mississippi River valleys. As meltwaters diminished, the deeply eroded river valleys aggraded substantially to about the present levels. Prior to impoundment, the broad floodplain of the river was complex matrix of depressions, secondary channels, natural levees, islands, and shallow lakes. Since impoundment, a relatively thin veneer of silts, clays, or sands has been deposited over most of the river bottom within the pool. The sedimentation of fines (clay and silt) is generally greater in the slow moving backwater areas than in the major side channels and main channel portions of the impounded area. The bluffs of the UMR valley along Pool 10 are composed of exposed Lower Paleozoic sedimentary rocks, dominantly carbonates (limestones and dolomites) and sandstones, overlain by unconsolidated materials of Quaternary (Upper Cenozoic) age loess of the earlier glacial advances. This stretch of the river lies within what is called the Driftless Area, a region of Northeast Iowa, Northwest Illinois, Southeast Minnesota, and Southwest Wisconsin that was not covered by advances of the Wisconsin ice sheet. Generally, project area soils are bottomland soils of alluvial origin. Alluvial bottomlands have soils made up of layers or lenses of sand, clays and silts deposited following periodic flooding. In areas of annual flooding, there is little soil development since humus material is removed or covered annually. A grey layer (Wilde 1940) of sticky fine clay with blue-green mottling from reduced iron is present in all bottomland soils. It indicates poor internal drainage and anaerobic soil conditions. Generally, alluvial soils have been in place long enough for trees and other plants to grow, but are located in frequently flooded areas and are subject to change. Higher lands on natural levees or outwash terraces have sandy loam soils. The St. Paul District completed six borings within the McGregor Lake area. The WDNR also completed a number of sediment probes within the same general area. These explorations 16

28 revealed that the upper layer is a very soft, flocculent material, which will be referred to as the semi-solid layer. Below the semi-solid layer, a thin layer (4 to 6 feet) of a dirty sand was encountered in the St. Paul District borings that were near the shoreline. The dirty sand consisted of a silty, clayey sand or a sandy silt. Below this, a soft, fat clay was typically encountered to the termination of the borings. The borings in the middle of the lake did not indicate any dirty sand, only a soft, fat clay below the semi-solid layer. The semi-solid layer is not expected to have much strength and will behave more like water than a soil. The semi-solid layer is likely to be 25% to 50% solids and the rest water. This means if used as the fine material, considerable dewatering will be required and shrinkage of 50% to 75% could be expected. The semi-solid layer will not support much load, if any, and will likely be displaced by any fill material. For more details regarding the borings and foundation assessment, see Appendix G Geotechnical Analysis. SEDIMENT TRANSPORT Sediment transport in the project area is affected by upstream sediment loads and local hydraulic conditions. Variation in upstream sediment loads occur due to seasonal patterns of river discharge and daily patterns of wind driven wave action. McGregor Lake can best be described hydraulically as a seasonally connected system. During low flow conditions, sediment can enter the lake only at its downstream end due to diffusive processes such as eddies and stage variation, however both of these processes are probably very small sources of sediment. Analysis of stage variation and the potential for sediment inputs indicates very small amounts of sediment and inspection of aerial photos doesn t indicate any tendencies for eddies to form at the downstream opening to the lake. For higher flow conditions, the natural levee that separates McGregor Lake is overtopped and sediment enters the lake advectively (i.e. carried by inflows). This overtopping occurs at discharges less than a 50-percent annual flood chance. The total bed material (i.e. sand) load in this reach of the UMR is approximately 130,000 tons/year (St. Paul District Sediment Budget, 2003). Downstream fining of main channel sediments occurs from lower Pool 8 to the Wisconsin River with sediments adjacent the project area consisting of fine sands. This low bed material load and the relatively fine sediments adjacent to the project area are partly due to upstream sediment sinks including backwater deposition and dredging, but are also natural since the Wisconsin River delta created a backwater affect which reduced hydraulic energy and sediment transport in this reach of the UMR. The lack of significant dredging or significant channel training structures upstream of the project area are artifacts of the reduced energy regime caused by the Wisconsin River backwater. The USGS gage at McGregor Iowa is located across the river from the project area. From 1976 to 2002, the St. Paul District funded the collection of water samples to determine the suspended sediment concentration (SSC) at this gage. The average growing season (May Sept) SSC at this gage was 34 mg/l over this time period. Although this is a relatively low concentration, significant variations in SSC occurred during low to moderate flow conditions, with many measured concentrations over 100 mg/l. This could reflect the effects of wind driven wave action and the resulting sediment flux from lower Pool 9. The McGregor data indicates a downward trend in both SSC and suspended sediment load during the 1976 to 2002 time period. Geomorphic processes in the project area vary in magnitude depending on location, elevation, and time frame. McHenry et al. (1975) found that sediments, as fines, are a continual threat to the use of backwater lakes and slack water pools as biological habitats. In Pool 10, using the radioisotope Cs-137 as a sediment marker, he found sediment deposition rates of 3.5 cm/year and 4.2 cm/year for the years 1955 to 1975, and the years 1963 to 1975 respectively and suggested that action was needed in the next quarter century for the lakes and pools to continue to function as viable habitat. This work was done over 40 years ago, and while it helped to focus 17

29 attention on the problems associated with excess sediment, the deposition rates obtained seem to be implausibly high. For example, if the value of 4.2 cm/year were assumed to be correct, 5.5 feet of sediment deposition would have occurred between the years 1975 and There is no detailed research on existing conditions for sediment deposition/erosion rates in the project area; however several studies in nearby river reaches provide some insight on deposition rates. Rogala et al. (2003) studied erosion and deposition in Pool 8, approximately 50 miles upstream of the project area, and determined a pool-wide net deposition rate of 0.27 cm/year for the years 1997 to It was noted that the deposition rates they were finding were much lower than those of previous researchers including McHenry s work in Pool 8. For the Upper Mississippi River Cumulative Effects Study (2000), net deposition rates in lower Pool 11, approximately 30 miles downstream of the project area were found to have changed from 1.56 cm/year for the time period to 0.34 cm/year for the time period Sediment Cores obtained in isolated backwater lakes, in Pool 10, approximately 10 miles downstream of the project area resulted in estimated post-impoundment sedimentation rates of 0.63 and 0.73 cm/yr (Theis and Knox, 2003). Benedetti (2000), also doing research in Pool 10 found deposition rates of 0.43 to 1.0 cm/yr for the time period 1963 to Collins and Knox (2003) found that most floodplain landforms have maintained the same general configuration through time, but isolated backwaters declined in total area after 1896, likely due to sedimentation. Future geomorphic change in the project area will continue to include natural levee erosion and sediment deposition; however the rate of change will be relatively low. The decreasing sediment loads at the McGregor gage and the net deposition rates found in other nearby river reaches more recently seem to support a low and decreasing rate of sediment deposition. Reconnaissance of the area seems to support the assumption that geomorphic change is occurring very slowly. Delta formation, a common process in other reaches of the river where significant amounts of water and sediment are conveyed into backwater areas, is not apparent in the project area. This apparently is due to the reduced bed material (i.e. sand) load in this reach of the river. If a net deposition rate of 0.5 cm/year were assumed for the project area, a total of 25 centimeters or 10 inches of net deposition would occur over the next 50 years. This suggests that project features such as dredging should be effective for the entire project life. CHANNEL MAINTENANCE ACTIVITIES This section of the UMR includes the 9-foot commercial navigation channel maintained by the St. Paul District. Adjacent to the project area, the navigation channel includes the UMR main channel on the west, as well as the East Channel. The navigation channel in this reach is maintained primarily through the minimum pool elevation established by the operation of LD 10. Because of the relatively low transport of sand size sediment through this reach, minimal training structures were needed and dredging is rarely required. There are a few marginal navigation channel reaches upstream of the project area that have required one or two dredging jobs over the last 40 years. More extensive dredging occurs downstream of the project site at the McMillan Island dredge cut (approximately RM 618 to 619). The McMillan Island dredge cut is typically dredged in about half of the years (47% of the time), with an average of about 35,000 to 40,000 cubic yards removed per dredging job. Historically, this material has been temporarily stored at the adjacent McMillan Island dredged material placement site prior to permanent placement elsewhere. As a part of dredging activities, St. Paul District actively works to find permanent placement options for dredged sand. This presents an opportunity to use dredged sand for habitat enhancement purposes, an approach that often has been employed when constructing habitat islands, floodplain forest features, or similar terrestrial habitat features. 18

30 2.10. LAND COVER AND PLANVIEW CONDITIONS The USGS Upper Midwest Environmental Sciences Center created several high-resolution land cover data sets for the UMR. These surveys involve the formal classification of cover types and were available for the project site and its surroundings for years 1890, 1975, 1989, 2000, and 2010 (Plates 2 thru 6). For specific details on the media and methods used, please visit resource_mapping_lcu.html. The 1975, 1989, 2000, and 2010 land cover data sets were developed from aerial photo interpolation (Table 6). A land cover map developed from the 1890 Mississippi River Commission high-resolution survey was also available but appeared too indiscriminate for valuable comparison with the land cover maps produced from aerial photos. Table 6. Cover Type Acreage by Year for the Project Area Open Water Submersed Aquatic Veg Rooted Floating Aquatics Sand/Mud Deep Marsh Shallow Marsh Wet Meadow Wet Forest Wet Shrub Developed Road/Levee Review of basic aerial photographs suggests relatively stable land form conditions. Plate 1 provides the 2017 aerial photograph, while Plate 7 provides a photograph from the 1930s. It appears that prior to lock and dam operation, McGregor Lake may have been almost disconnected from the river during low-flow conditions. Similarly, the amount of aquatic habitat may be slightly greater post lock and dam, with less variability in seasonal water elevations. Since at least the 1930s the project area has included two bridges crossing through the middle just north of McGregor Lake (Plate 7). By 1990, this was reduced to a single bridge for U.S. Hwy 18. Remnants of the second bridge can still be seen immediately north of the Hwy 18 crossing VEGETATION Unlike many lower reaches of the pools in the UMR, which have become an open expanse of water due to increased stage and island erosion, much of the floodplain forest in lower Pool 10 has persisted post-impoundment. From floodplain forest cover in lower Pool 10 has experienced a 27 percent decrease. While this is a significant loss, it is relatively low compared to the 65 and 60 percent decrease experienced in Pools 8 and 9, respectively, over the same period of time. Resource managers report that tree species diversity within the floodplain has also significantly decreased. FLOODPLAIN FOREST The predominant tree species in Pool 10 include a mixture of silver maple, ash, cottonwood, black willow, elm, and river birch. A wide variety of floodplain and riverine habitats within Pool 10 has allowed the development of a diverse vegetative assemblage under present-day conditions. Swamp white oak are common species at the higher elevations of the floodplain. 19

31 Typical floodplain forest canopies are dominated by silver maple, cottonwood, American elm, black willow and green ash. The understory in these areas consists primarily of Canadian woodnettle, whitegrass, poison ivy, wild grape and clearweed. In transitional zones between aquatic and terrestrial habitat (e.g., sandbars and mudflat areas), dense stands of sandbar willow and buttonbush are common. The diversity of species comprising the floodplain forest has been impacted significantly since impoundment. Flood frequency, duration, and height affect species composition in floodplain forests (Menges 1986). Areas flooded less than 40 days during the growing season support a more diverse community of tree species (De Jager et al. 2012; Knutson et al. 1998). Under natural conditions, water levels would drop considerably after spring floodwaters subsided, allowing less flood-tolerant species to grow within the floodplain. Lock and dam operations along the UMR have increased the water levels at low discharges, altering the frequency and duration of flooding at lower elevations in the pools. At the McGregor project site, the low flow (75% exceedence) is approximately two feet higher post-dam than pre-dam. More flood-tolerant species, particularly silver maple, have become increasingly dominant at these lower elevations. The 1890s Mississippi River Commission map of the project area identifies willow, maple, and elm species in the upland portions of the project area. Areas that are identified as willow in this map currently have forests of silver maple, swamp white oak, and other species. It is possible that forests in this area were harvested for fuel wood, either for the nearby towns of Marquette, Prairie du Chien, and McGregor, or for steamboats. A forest inventory conducted in 2015 found that 85% of the trees surveyed were silver maple (Figure 5). Green ash, swamp white oak, cottonwood, American elm, black willow, and river birch were each 1-4% of the surveyed individuals. Other species present on the site, but comprising less than 1% of the total include hackberry, red mulberry, box elder, bitternut hickory, catalpa, hawthorn, and black locust. Certain areas of the McGregor Lake area have very high species diversity compared to typical floodplain forests. The number and size of swamp white oak in several areas is unique, and there are many seedlings present, which is unusual. There are multiple hackberries and bitternut hickory trees on some of the higher ridges. Forest Inventory Tree Species Relative Abundance 2% 2% 1% 4% 3%3% 85% Silver maple Green ash Swamp white oak Cottonwood American elm Black willow River birch Figure 5. Tree Species Relative Abundance from Forest Inventory for the Project Area. 20

32 AQUATIC VEGETATION Anecdotal observations within McGregor Lake suggests the presence of submergent and emergent aquatic vegetation may be substantially less than other similar backwater lakes within the pool. High turbidity levels in the lake may be the limiting factor for aquatic vegetation. The lake substrate is very flocculent and is easily suspended by wind and wave action, contributing to turbidity issues. The loose sediment may also be a challenging environment for plants to establish. INVASIVE SPECIES Invasive animals in the project area include (but are not limited to) zebra and quagga mussels, Asian carp species such as grass, bighead and silver carp; rusty crayfish, and other species. A comprehensive list of invasive fish, invertebrates and other species for the UMR basin is provided in USACE (2013). Invasive plants found in Pool 10 include reed canary grass, common buckthorn, purple loosestrife, Eurasian water milfoil, and curly-leaf pondweed. The USFWS and State resource agencies are pursuing methods to control the spread of invasive species on lands they manage. Common buckthorn has been identified in the higher elevation areas of the forest FISH AND WILDLIFE RESOURCES FISH A total of 92 fish species are reported to inhabit pool 10, 34 of which are considered common or abundant (Steuck et al. 2010). An additional 11 species were historically found in the pool but have not been recorded in recent years. Common game species include walleye, sauger, northern pike, channel catfish, largemouth and smallmouth bass, bluegill, and white and black crappie. Common nongame fish include the freshwater drum, common carp, and various species of gar, redhorse, buffalo, and a wide variety of minnows. Catfishes, buffaloes, and common carp are the primary fish of commercial interest. Within the project area, largemouth bass, smallmouth bass, bluegill, crappie and walleye use side channels and backwaters for all life functions. Northern pike, white bass, carp and buffalo use these same habitats for rearing, wintering and spawning. Within the project site (Sturgeon Slough and Lover s Lane), overwintering fish surveys have been conducted by the WDNR in 2001, 2002, , 2008, & A total of 22 species were sampled during the surveys. The most commonly surveyed fish species included bluegill, black and white crappie, largemouth bass, gizzard shad, and spotted sucker. Fixed electrofishing runs in the most likely overwintering sites were conducted during every year of sampling in Sturgeon Slough and every year except for 2002 & 2012 in Lover s Lane. In Sturgeon Slough the average catch per unit effort (CPUE) of age 1 plus bluegill was highest in 2001 and lowest in 2004 with 306 and 15 fish per hour, respectively. The CPUE for age 1 plus largemouth bass was also highest in 2001 and lowest in The CPUE largemouth bass was 102 and 15 fish per hour, respectively. In Lover s Lane the average catch per unit effort (CPUE) of age 1 plus bluegill was highest in 2001 and lowest in 2004 with 404 and 0 fish per hour, respectively. The CPUE for age 1 plus largemouth bass was also highest in 2001 and lowest in The CPUE largemouth bass was 92 and 4 fish per hour, respectively. These numbers are generally considered low for overwintering habitat on the UMR, suggesting limited habitat value. Plate 10 was provided courtesy of the WDNR (Jeff Janvrin, 2017) and identifies areas known with at least some periodic overwintering habitat in Pool 10. While this may appear to contain a number of sites, many of these are relatively small and of marginal value at best. While these sites may offer 21

33 modest quality during some years, more severe winters may result in poor quality and poor overwinter survival for many species. WILDLIFE Floodplain forest areas in the project vicinity contain a rich assortment of mammalian species, particularly those associated with and dependent on water. Raccoon; muskrat; beaver; river otter and mink are common inhabitants frequenting woodlands; wet meadow areas and aquatic habitats alike. White-tailed deer; red fox; gray fox; opossum; striped skunk; gray squirrel; fox squirrel; Eastern cottontail rabbit; and various smaller rodent species are also found in bottomland habitats, most generally in woodland and for marsh sedge meadow areas. Floodplain forests within Pool 10 are used extensively by nesting migratory birds including the prothonotary warbler, cerulean warbler and American redstart. The river bottomlands serve as breeding areas for many species of marsh dwelling birds as well. Extensive wood duck nesting and brood-rearing habitat is available. Hooded mergansers, mallards, Canada geese, herons, shorebirds and marsh passerines (e.g. red-winged blackbird and marsh wrens use floodplain forest and marsh areas for nesting and brood-rearing. Dabbling ducks use shallow backwater areas, feeding on submerged pondweeds and the seeds of emergents. Diving ducks use more open water areas feeding on submerged pond weeds, wild celery, mollusks and invertebrates. Many species of waterfowl use the Mississippi River strictly for loafing and roosting, feeding primarily in adjacent upland areas (i.e., cornfields, grain fields). Backwaters in the project area provide feeding habitat for wading birds from rookeries both upstream and downstream. An active nesting colony of great blue heron, double-crested cormorant, and great egret exists at approximately UMR mile 639.6, on the Wisconsin side. Garnet Lake between UMR mile and UMR mile is heavily used by wading birds feeding on fish species. Historically, Garnet Lake had heron rookeries nearby, and today it supports a black tern nesting colony. Marsh and shorebird species, passerines, aquatic furbearers, and reptiles also favor many of the same habitats. Turtle, muskrat, and beaver are commonly trapped in the biologically rich Lower Bottoms. Information on reptilian and amphibian species that inhabit the area is limited. Species of turtles, water snakes, mud puppies, salamanders, frogs and toads are all commonly found in marsh/sedge meadow areas and aquatic habitats. Turtles use sandbar areas as nesting habitat, while life stages of mud puppies, salamanders, frogs and toads use backwaters and marshes. Several bird species occur in Pool 10 that are of special interest because of their status or ecological importance. Foremost among these is the bald eagle, which was recently de-listed from the Federal list of threatened species and has increased dramatically in recent years. Eagles use Pool 10 year-round. In addition, the pool is part of an important migration corridor. Eight active bald eagle nests are in the general project area (Plate 11). The eagle is protected under the Federal Bald and Golden Eagle Protection Act. AQUATIC INVERTEBRATES The diverse invertebrate assemblage within Pool 10 can be attributed to a wide variety of habitats available. Suitable lentic, lotic and transitional habitats are available for many different types of organisms. Also, rocks associated with shoreline protection (as well as woody debris accumulated in backwater areas) provide a substantial amount of hard, stable substrate for many highly productive taxa. These taxa can represent a substantial dietary item for many fishes and other vertebrates. Other invertebrate taxa attach to aquatic vegetation in backwater areas. Many of these taxa serve as an important food source for waterfowl. 22

34 Approximately 35 species of native freshwater mussels currently inhabit pool 10, including the federally-endangered Higgins eye pearlymussel (Lampsilis higginsii), spectaclecase (Cumberlandia monodonta), and sheepnose (Plethobasus cyphyus); as well additional Iowa or Wisconsin state-listed species: round pigtoe (Pleurobema sintoxia), pistolgrip (Tritogonia verrucosa), strange floater (Strophitus undulatus), butterfly (Ellipsaria lineolata), yellow sandshell (Lampsilis teres), wartyback (Quadrula nodulata), monkeyface (Quadrula metanevra), rock pocketbook (Arcidens confragosus), and fawnsfoot (Truncilla donaciformis) (Kelner 2017). Few mussel surveys have occurred within the interior of the project area. However, the nearby East Channel Essential Habitat Area (EHA) for the endangered Higgins eye mussel has been sampled extensively and could be a good indicator for native mussel species in the area. Historically the East Channel EHA had been one of the most valuable mussel habitats on the entire UMR, supporting the largest known population of Higgins eye (USFWS 2004). Since 1985 thirty species of native mussels have been collected in the East Channel EHA (Mussel Coordination Team 2012). The EHA includes all aquatic areas of the main channel and the east channel within the project area. It does not include McGregor Lake or the secondary channel habitat within the island complex between the Main and East channels (Figure 6). Figure 6. Location of the East Channel Essential Habitat Area for Higgins eye mussel in blue outline. 23

35 Native mussels in pool 10 have been severely impacted by the invasive zebra mussel since first appearing in the 1980s. Surveys conducted within the East Channel showed that zebra mussel densities increased tenfold between 1999 and 2000, and densities greater than 10,000 zebra mussels/m 2 were observed (Miller and Payne 2001). The substrate of the East Channel is covered with empty zebra mussel shells several feet deep in some places. Since 2003 zebra mussel densities have been relatively low. Zebra mussels have a high reproductive rate and grow to sexual maturity very quickly and future zebra mussel population sizes are unpredictable. A recent survey in 2017 found 22 live native mussel species and a mean density of 9 mussels per square meter (Kelner, unpublished results of field surveys). This is higher than any year since before the arrival of zebra mussels in the mid-nineties, indicating that native mussels have rebounded since the zebra mussels declined. Fingernail clams thrive in areas of pool 10 that have silt bottoms and adequate oxygen. They are important food items for both waterfowl, especially diving ducks, and several species of fish. Pool 10 insect fauna is dominated by immature stages of mayflies, midges, and caddisflies, indicative of high dissolved oxygen levels. Being efficient converters of detritus, aquatic insects are an important link in the food web, providing food for fish and waterfowl. THREATENED AND ENDANGERED SPECIES The pool has many species of fish, mussels, plants, birds, mammals, and others listed by the States of Wisconsin, and Iowa as endangered, threatened, or of special concern. Several federally-listed species or candidate species occur in Crawford County, Wisconsin, and Clayton County, Iowa (Table 7); USFWS 2018). These species may occur within the project area and may be affected by the project. Table 7. Species Listed Under the Federal Endangered Species Act Within or Near The Project Area. Note that northern wild monkshood, western prairie fringed orchid, and Iowa Pleistocene snail have been identified in Clayton County, Iowa. However, these are upland species, not found in the floodplain and thus not affected by the project. Common Name Higgins Eye Sheepnose Mussel Spectaclecase Scientific Name Lampsilis higginsii Plethobasus cyphyus Cumberlandia monodonta Group Clams Clams Clams Status Endangered Endangered Endangered Location Listed Clayton County, IA Crawford Co, WI Clayton County, IA Crawford Co, WI Clayton County, IA Crawford Co, WI Rusty Patched Bumble Bee Bombus affinis Insects Endangered Crawford Co, WI Northern Long-Eared Bat Myotis septentrionalis Mammals Whooping Crane Grus americana Birds Eastern Massasauga Sistrurus catenatus Threatened Experimental, Non-Essential Clayton County, IA Crawford Co, WI Crawford Co, WI Reptiles Threatened Crawford Co, WI As previously mentioned, the Higgins eye, sheepnose, and spectaclecase mussels have been identified as endangered mussel species occurring in pool 10. Though Higgins eye have been found in the nearby East Channel EHA, the area within McGregor Lake and similar backwater areas typically would not be suitable habitat given the substrate and flow conditions. Surveys of McGregor Lake and the side channels in the project area were completed in No species of special concern were found in the project area, except in the East Channel. 24

36 The Wisconsin and Iowa DNRs provided lists of state-listed species, compiled in Table 8. Where state-listed species were already listed above as federally listed, these were not replicated in the state list. Potential impacts to threatened and endangered species will be covered in Section Table 8. State-Listed Threatened and Endangered Species Not Federally Listed. Species Name Scientific Name Group Iowa Status Wisconsin Status American brook lamprey Lampetra appendix Fish T Bald eagle Haliaeetus leucocephalus Birds SC Big brown bat Eptesicus fuscus Mammals T Black redhorse Moxostoma duquesnei Fish T Blanchard s cricket frog Acris blanchardi Amphibian E Blanding s Turtle Emydoidea blandingii Reptiles T SC Blue sucker Cycleptus elongatus Fish T Burbot Lota lota Fish T Butterfly mussel Ellipsaria lineolata Clams T Channel shiner Notropis wickliffi Fish SC Chestnut lamprey Ichthyomyzon castaneus Fish T Common musk turtle Sternotherus odoratus Reptiles T Creeper Strophitus undulatus Clams T Eastern pipistrelle Perimyotis subflavus Mammals T Grass pickerel Esox americanus Fish T Kentucky warbler Geothlypis formosa Birds T Lake sturgeon Acipenser fulvescens Fish E SC Little brown bat Myotis lucifugus Mammals T Mud darter Etheostoma asprigene Fish SC Mudpuppy Necturus maculosus Amphibian T Pirate perch Aphredoderus sayanus Fish SC SC Pistolgrip Tritogonia verrucosa Clams E Prothonotary warbler Protonotaria citrea Birds SC pugnose minnow Opsopoeodus emiliae Fish SC Purple wartyback Cyclonaias tuberculata Clams T Red-shouldered hawk Buteo lineatus Bird E Round pigtoe Pleurobema sintoxia Clams E Smooth softshell Apalone mutica Reptile SC Southern flying squirrel Glaucomys volans Mammals SC Timber rattlesnake Crotalus horridus Reptile SC Weed shiner Notropis texanus Fish E SC Western sand darter Ammocrypta clara Fish T Wood turtle Glyptemys insculpta Reptile T Yellow sandshell Lampsilis teres Clams E E = Endangered, T = Threatened, SC = Special Concern CULTURAL RESOURCES Cultural resources are a major component of the Upper Mississippi River Valley and are integral, nonrenewable elements of the physical landscape. The Area of Potential Effect (APE) has been identified as McGregor Lake and the adjacent floodplain and secondary channels that make up the island complex encompassing McGregor Lake between the main and east channels 25

37 (Plate 1). There are over 100 historic properties within one mile of the project and 11 historic properties and 5 wingdam structures within the APE (SHPO files 2018). Significant properties, like those present within the APE, contribute to our knowledge of the past. Preserving, or minimizing the degradation of these important resources is one of the responsibilities of the Corps and other agencies. The Pool 10 locality has a long history of archaeological investigations. The first known report was completed by Richard Taylor in 1838 and subsequent investigations dating to the 1800s and early 1900s by the Bureau of American Ethnology, Northwestern Archaeological Survey, and other groups who mapped upland sites and excavated burial mounds (e.g. Taylor 1838, Thomas 1894, Lewis n.d., Orr 1927, 1936, Kolb & Boszhardt 2004). Focus on upland areas continued in the Prairie du Chien locality until the 1970s when surveys started to shift focus to floodplain areas (e.g. Halsey 1972, Benn 1978, Stoltman 1979, 2004, Kolb & Boszhardt 2004). The Corps and other agencies have sponsored several archaeological investigations within the pool for various projects, including dredge material placement sites, flood control features, shorelines surveys, phase II archaeological investigations, erosion monitoring, and environmental management programs (e.g. Benn 1975, Wahls 1990, Holtz & Boszhardt 1995, Florin & Madigan 2000, Jalbert 2002, Stoltman 2003, 2004, Scott 2010). Literature-based overviews such as geomorphological studies to assess archaeological site potential, navigational feature mapping, and shipwreck locations have also been completed (e.g. Overstreet 1984, Church 1984, Jensen 1992, Arzigian & Dowiasch 1995, Madigan & Schirmer 2001, Kolb & Boszhardt 2004, Benn & Lee 2005). Cultural resource sites within Pool 10 exist on a variety of landforms including uplands, terraces, islands, natural levees, deltas, submerged backwater lakes, and the river channel. Identified properties in Pool 10 include precontact resources such as single artifact finds, lithic and artifact scatters, village sites, archaeological districts, petroglyphs, rock shelters, burials and burial mounds and cemeteries. Historic resources include fur trade sites, townsites and farmsteads, cemeteries, historic standing structures, historic debris scatters and middens, historic districts, shipwrecks, and navigational structures (e.g. wingdams) (SHPO files 2018, Madigan & Schirmer 2001). Several sites within Pool 10 are listed on the National Register of Historic Places (NRHP) and over 100 sites are eligible for listing (SHPO files 2018, Madigan and Schirmer 2001). The sites identified within the APE include a habitation site, a mound group, two Native American historic shell middens, two historic clamming middens, one historic clamming midden with a precontact component, and four precontact artifact scatters (Madigan and Schirmer 2001, Stoltman 2004, SHPO files 2018). The McGregor Lake project area and nearby historic properties have been impacted by submersion and erosion as a result of construction of LD 10 in 1937 and subsequent operation and maintenance of the 9-Foot Channel Project. Most of the resources in Pool 10 were identified in the 1980s by Richard Wahls, Robert Boszhardt, and James Stoltman (Stoltman & Theler 1980, Boszhardt 1982, Wahls 1989). Several cultural investigations have been conducted within the APE including Phase II investigations. These investigations resulted in one site being listed on the NRHP, one determined eligible for listing on the NRHP, and one not eligible for listing on the NRHP (Stoltman 2004, Scott 2010). There are several sites that need additional investigations to determine their eligibility. Until further investigation, the Corps considers all sites potentially eligible for listing on the NRHP RECREATION AND AESTHETICS The natural character and the relatively good water quality in Pool 10 contribute to its heavy recreational use and aesthetic desirability. The area is in close proximity to Prairie du Chien, Wisconsin; and Marquette and McGregor, Iowa. Twelve of the 36 boat landings available within 26

38 Pool 10 are located within a mile of the project area. The area is heavily used for fishing, boating and hunting. A commercial fishery is also active. Other important recreational activities in the pool include hiking, picnicking, camping, swimming, canoeing and trapping. A number of high quality recreational beaches, public day-use and camping recreation facilities, and private marina facilities are available. Sturgeon Slough Hiking Trail lies within the project area and offers 0.7 miles of hiking trail as well as a wildlife viewing area. This is accessible via a parking area right off U.S. Highway 18 in the middle of the project area. The Wisconsin DNR operates Wyalusing State Park just downstream at the Wisconsin River Delta. The State of Iowa operates Pikes Peak State Park on the top of the bluff overlooking the project area. The National Park Service operates Effigy Mounds National Monument approximately 7 miles north of the project area in Allamakee County, Iowa. This monument preserves over 200 prehistoric mounds built by Native Americans. Wyalusing and Pikes Peak both contain mounds as well. A large amount of Federal land is in Pool 10; most of this land is managed for fish and wildlife as part of the Upper Mississippi River National Wildlife and Fish Refuge SOCIOECONOMIC SETTING McGregor Lake is located within Pool 10 of the Mississippi River at River Mile 634. Across the navigation channel to the east is the town of Prairie du Chien, Wisconsin (2010 population of 5,911). Nearby smaller towns on the Iowa side include McGregor (2010 population of 871) and Marquette (2010 population of 375). Surrounding counties include Crawford and Grant on the Wisconsin side of the river and Clayton and Allamakee on the Iowa side. The area is generally rural in nature with agriculture being the major industry in the local economy. Population: Population levels in recent decades have been relatively stable for the Wisconsin counties while the state as a whole has grown steadily. The Iowa counties have experienced moderate to significant population decline while the state has grown slowly. In comparison the nation as a whole has grown at a considerably faster pace. The trends from 1980 to 2010 are presented in Table 9. Employment: Important industries in the local economy in terms of employment include agriculture and manufacturing. They employ a larger percentage of the labor force than the nation as a whole. On the other hand, industries employing a lower percentage of the labor force than the U.S. include the professional, scientific, and management services sector and the finance, insurance, and real estate sector. Recent county unemployment rates have been significantly less than national averages. During the period they averaged from 4.5% to 7.9% while the nation s unemployment rate averaged 9.3%. Income: Per capita income for the counties lags significantly behind that of their respective states and even more so behind the U.S. Interestingly, however, while the U.S. per capita income is higher, its poverty rate (for All People) is also higher than the counties (Table 10) Table 9. County and State Population Trend County/State % Change Wisconsin 4,705,642 5,686,986 5,363,675 5,686, % Crawford Co. 16,556 15,940 17,243 16, % Grant Co. 51,736 49,264 49,597 51, % Iowa 2,913,808 2,776,755 2,926,324 3,046, % Clayton Co. 21,098 19,054 18,678 18, % Allamakee Co. 15,108 13,855 14,675 14, % United States 226,545, ,709, ,421, ,745, % 27

39 Table 10. Per Capita Income and Poverty Rate by County/State (2010). Allamakee Clayton Iowa Crawford Grant Wisconsin U.S. Per capita Income 23,392 24,378 26,545 22,331 21,391 27,426 28,051 PCI - % of U.S. 83.4% 86.9% 94.6% 79.6% 76.3% 97.8% Poverty Rate Source: American Community Survey 5-Year estimates Transportation: Transportation corridors bound both sides of the floodplain in this vicinity of Pool 10. This includes a rail line on either side of the river and a state highway on the Wisconsin side (Hwy 35). U.S. Highway 18 runs directly through the project area. In addition, the river serves as a corridor for commercial navigation of barge traffic via the 9-foot navigation channel as authorized by Congress. Barge traffic transports a wide variety of essential goods on the UMRS. Agricultural commodities, petroleum products, and coal are the leading cargoes, with farm products accounting for approximately half the total tonnage shipped HAZARDOUS, TOXIC, AND RADIOACTIVE WASTE From a contaminants perspective, sediment quality is generally good in Pool 10. Main channel sediments are primarily medium to coarse sands with only trace amounts (generally less than 3 percent by weight) of silts and clays. Sand, silt, and clay sediments are found within defined secondary channels, while finer silt and clay materials are found in marshy backwater areas. Levels of pesticides and other chlorinated hydrocarbons are generally below detection limits in all main channel sediments and detected at low levels in backwaters. Sullivan and Moody (1996) conducted a pre- and post-1993 flood (1991 and 1994) longitudinal (Pools 1 through 11) survey of contaminants. This study compared the data to the Ontario Ministry of Environment and Energy s Sediment Quality Guidelines (Persaud et al. 1993). Nitrogen was found above Ontario s lowest effect level guideline both pre- and post-flood, but was typical of concentrations in adjacent pools. Polychlorinated biphenyls (PCBs) and chlorinated pesticides were found at low levels, below Ontario s lowest effect level guideline. In comparing backwater areas for this reach to other reaches in the UMR, metals concentrations were found at levels within the expected ranges. Sediment in McGregor Lake was sampled in 2014 and compared to the WDNR s consensus based sediment quality guidelines (WDNR, 2003). The guidelines have a lower level of concern called the threshold effect concentration (TEC) at which toxicity to benthic-dwelling organisms is unlikely, an upper level of concern called the probable effect concentration at which toxicity is predicted to be probable, and a midpoint called Midpoint Effect Concentration. All the parameters were below the lowest threshold effect concentration (TEC), except mercury, manganese, and nickel. Mercury was undetected, but the lab s reporting level was higher than the TEC. Nickel just barely exceeded the TEC in one of three samples (24.3 mg/kg compared to a TEC of 23 mg/kg). Manganese levels were also above the TEC at 625 mg/kg compared to a TEC of 460 mg/kg, but this level of manganese is within the typical background levels for the UMR. All parameters were below the Midpoint Effect Concentration level. There are no concerns with using dredged material for habitat restoration features. North of the existing Highway 18, there are sections of an old embankment that once supported the highway before the current alignment. Soil from the embankment was tested for contamination. Polycyclic aromatic hydrocarbons (PAH) and manganese were detected in these samples. While these levels were not particularly alarming, the material does pose some risk for use in an aquatic environment, therefore use of the embankment material for features within the project area was not considered. 28

40 Acreage HISTORICALLY DOCUMENTED CHANGES IN HABITAT CONDITIONS The following documents the physical and vegetation characteristics of the project area at various points in time. No attempt was made to estimate the quality of fish and wildlife habitat that existed at these points in time. Changes from pre-lock and dam impoundment to current conditions have been documented. A brief discussion of general changes is provided below. A full discussion can be found in Appendix K 2014 Problem Appraisal Report. LAND COVER From the land cover data it appears that cover types have stayed relatively stable in the project area from 1975 to 2010 (Table 6 & Plates 3 thru 6). The two cover types that have varied to the largest extent are open water and submersed aquatic vegetation. During that time the acreage of open water decreased and was replaced primarily by submersed aquatic vegetation. However, it should be noted that land cover types such as those associated with submergent aquatic vegetation (SAV) and emergent aquatic vegetation (EAV) can vary greatly from year to year. 600 Cover Type Acreage by Year Figure 7. Changes in Cover Type for the Project Area from Wet shrub, developed, and road/levee cover types were excluded from the figure as acreages were minimal. EROSION The head of McGregor Island was protected with an offshore rock mound in 1995 through the Bank Stabilization HREP. Several locations within the project area show varying degrees of erosion. Two areas of erosion are the northeast and southwest corners of McGregor Lake, where the natural levee embankment has been eroding such that flows are entering the lake at lower water surface elevation than previously. It is thought that these two locations will continue to erode until the lake is continuously connected to inflows, even at low water levels. Other areas of the bank have erosion occurring, but the rate and consequences of erosion are not clear. 29

41 2.18. FACTORS INFLUENCING HABITAT CHANGE GENERAL A number of factors have been identified that are believed to be influencing habitat changes in the project area. Many of these factors are synergistic, combining to affect both the physical and biological environment. GEOMORPHOLOGY AND HYDROLOGY The closure of LD 10 raised low flow (75% exceedence) water surface elevations approximately 2 feet. This rise in water surface increased the size of McGregor Lake and converted plant communities at lower elevations to wetter types. Wet shrub willow communities likely transitioned to emergent aquatic vegetation or open water, mid-elevation forests would have transitioned to a wetter and less diverse forest composition, and emergent and submersed aquatic vegetation would have transitioned to open water in areas that became too deep and turbid to support vegetation. According to the UMRR program s LTRM land cover maps, Pool 10 had about 14,000 acres of wet forest in 1890, and only 10,000 acres in In 1890 there were approximately 5,000 acres of shrub habitat, and in 2010 only about 100 acres. In the same timeframe, open water increased from about 10,000 acres to 13,000 acres. In the McGregor project area, the highest ridges likely were not significantly affected by the formation of Pool 10. These areas are 617 to 620 feet elevation, which is five to eight feet above the low flow elevation of 612. Water surface elevation was not significantly raised at the 25% exceedance flow, which remained at about 615. The two-year flood elevation was slightly higher post pool formation, increasing from 619 to 620. As described earlier, the higher elevation ridges support swamp white oak in many location in the project area, as well as hickory, catalpa, and hackberry in the highest locations, indicating that forests in these areas support a uniquely diverse tree assemblage. Pool formation changed the movement and deposition of sediments. Sand bars and mudflats decreased as the higher water surface covered the elevations at which these features had once formed during flood events. Backwaters became more connected to flowing channels, which likely increased the deposition of sediments into off channel areas. After European settlers converted large portions of the watershed to agriculture, sediment loads increased, delivering more into backwaters. More recently, water clarity has improved and sediment loads have decreased on the Upper Mississippi River, but many backwaters have legacy sedimentation and an accumulation of nutrients that can contribute to water quality and water clarity problems. 3. DEVELOPMENT OF PROJECT OBJECTIVES Chapter 3 identifies the McGregor Lake Project resource problems and opportunities as well as the objectives and constraints. Problem statements are concise characterizations of the broad issues that will be addressed with the project. Opportunity statements follow each problem and consist of an array of opportunities presented by the virtue of planning and construction activities occurring at the site. Opportunities can be directly related to solving the problem at hand, but can also be ancillary to the identified problem. From the list of problems and opportunities, objectives for the project are drafted and study specific constraints are identified. The success of the project planning is determined by the fulfillment of the objectives through identified alternative measures. 30

42 As part of the problem identification, the future without project (FWOP) condition is described. Following the discussion of resources problems, the goals and objectives for addressing these problems are described FUTURE WITHOUT-PROJECT CONDITIONS ESTIMATED FUTURE HABITAT CONDITIONS FLOODPLAIN FOREST Floodplain forest is one of the priority habitat types for our agency partners and is a focus for this project. As described above, the coverage of floodplain forest has significantly declined since the implementation of locks and dams on the UMR. The floodplain forest lost one of its most significant canopy trees, American elm, to Dutch elm disease in the 1970s. At present, ash trees are experiencing a similar decline due to Emerald Ash borer. Green ash is the second most common tree in the project area, and in the future, it is predicted to decline significantly. This will leave the forest with an even more reduced species diversity. Reed canary grass, an invasive grass that often outcompetes young tree seedlings, is found in small isolated patches, but does not appear to be problematic at this site. The reasons for this are unknown. Assuming that the site remains resilient to reed canary grass, the forest will continue to persist into the future, but will have a low species diversity, making it very vulnerable to any disease or pest that might attack silver maple. If some pathogen were to impact maple in the way that ash and elm have been impacted, the floodplain forest would undergo a drastic decline MCGREGOR LAKE The Bluegill Winter Habitat Suitability Index Model in the Upper Mississippi River (Palesh and Anderson 1990) was used to characterize future habitat conditions for McGregor Lake, as well as other off-channel aquatic habitat in the project area. This model has been approved as a Certified Planning model as required by USACE Engineering Circular Ideal backwater overwintering habitat is described later in this report, but is represented with adequate surface area that is at least 4 in depth; DO levels at or above 5 mg/l; water temperatures of 4 C, and negligible water velocities. The overwintering model considers these key variables to generate a suitability index ranging between 0.1 (minimal habitat) and 1.0 (perfect overwintering habitat). It should be noted that habitat quality can vary from year to year based on water quality differences (e.g., DO, temperature and velocity), and marginal overwintering sites can provide habitat during some years. As such, model suitability s also vary based on model input. For the purpose of this analysis we used dissolved oxygen, temperature and velocity values that have been recently observed in McGregor Lake during winter conditions. Model input for water depth was taken directly from existing bathymetry information. Based on existing information outlined in Section 3, McGregor Lake would have a Habitat Suitability Index score (HSI) score of 0.5 to 0.6 under existing conditions. These HSI values generally appear greater than actual habitat conditions, with late-fall fishery surveys suggesting McGregor Lake is often a poor overwintering site. Overwintering habitat model suitability scores in McGregor Lake would be expected to markedly decrease in the future. Over time, the natural levee that forms the barrier between McGregor Lake and the East Channel is expected to erode from periodic overtopping. This would eventually lead to a permanent connection between the East Channel and McGregor Lake at the northeast corner of the lake. A permanent connection would result in increased sedimentation and shallower backwater depths, reducing habitat quality through loss of physical space. It also 31

43 would reduce backwater temperatures to near freezing, and introduce flow during winter months. Any of these changes would also reduce habitat suitability of McGregor Lake, even if the model cannot project lower habitat suitability. Future without project conditions in McGregor Lake are project to have an HSI score of between 0.1 and 0.3. Overwintering habitat in adjacent off-channel aquatic areas may have similar habitat based on available data. The overwintering model suggests secondary channels and off-channel habitat adjacent to McGregor Lake may have poor existing suitability (HSI) between 0.1 and 0.5. Some overwintering has been observed, and suitability in these areas may be more variable with variability in temperature and current velocities. Minimum DO levels may be slightly higher helping to increase this suitability relative to McGregor Lake. Suitability scores within adjacent aquatic habitat would probably remain similar, or drop slightly in the future without a project due to loss of depth via sedimentation, and associated changes in water quality. This also generally agrees with late-fall fishery surveys which suggest Honeymoon Slough supports limited overwintering habitat compared to McGregor Lake. CLIMATE CHANGE Engineering and Construction Bulletin (USACE 2016) provides guidance for incorporating climate change information in hydrologic analyses in accordance with the Corps overarching climate change adaptation policy. It calls for a qualitative analysis and provides links to online tools that can be used in this qualitative analysis. The goal of a qualitative analysis of potential climate threats and impacts to Corps hydrology-related projects and operations is to describe the observed present and possible future climate threats, vulnerabilities, and impacts specific to the study goals or engineering designs. This includes consideration of both past (observed) changes as well as potential future (projected) changes to relevant climatic and hydrologic variables. For additional details on the climate change analysis completed for this study please see Appendix H. The U.S. Global Research Program s Third National Climate Assessment was completed in It states that: in the Upper Midwest extreme heat, heavy downpours, and flooding will affect infrastructure, health, agriculture, forestry, transportation, air and water quality, and more. Climate change will tend to amplify existing risks climate poses to people, ecosystems, and infrastructure. Direct effects will include increased heat stress, flooding, drought, and late spring freezes. Climate change also alters pests and disease prevalence, competition from non-native or opportunistic native species, ecosystem disturbances, land-use change, landscape fragmentation, atmospheric and watershed pollutants, and economic shocks such as crop failures, reduced yields, or toxic blooms of algae due to extreme weather events. These added stresses, together with the direct effects of climate change, are projected to alter ecosystem and socioeconomic patterns and processes in ways that most people in the region would consider detrimental. The Pool 10 discharge gage at McGregor, Iowa was used to analyze the change in the average annual peak discharge for the period of record The average annual discharge is shown in Figure 8. From 1938 to 2015, there has been a statistically significant increase in the average annual discharge for Pool 10. Although the trend line from 1981 to 2015 appears downward, it should be noted that the inter-annual variability in average annual discharge increased from 8,390 cfs ( ) to 11,110 cfs. In addition, ten of the eleven years for when average annual flows exceeded 50,000 cfs have all occurred since the early 1980s. This indicates that elevations higher than data suggests should be considered when designing potential project features. 32

44 Average Annual Discharge [CFS] Average Annual Discharge at McGregor, Iowa Gage (1938 to 2015) Linear (Average Annual Discharge 1938 to 2015) Linear (Average Annual Discharge 1938 to 1980) Linear (Average Annual Discharge 1981 to 2015) Calendar Year Figure 8. Average Annual Discharge at the McGregor, Iowa USGS Gage (Gage Number ) from 1938 to RESOURCE PROBLEMS AND OPPORTUNITIES One of the critical steps in the initial planning process is the identification of problems and opportunities associated within the geographic scope of the project area. Problem statements are concise characterizations of the broad issue that will be addressed with the project. Opportunity statements follow each problem and consist of an array of opportunities presented by the virtue of planning and construction activities occurring at the site of the problem. Opportunities can be directly related to solving the problem at hand, but can also be ancillary to the identified problem. From the list of problems and opportunities, objectives for the project are drafted. The success of the project planning is determined by the fulfillment of the objectives through identified alternative measures. Existing information was reviewed collaboratively among resource agency partners to identify habitat deficiencies for the project area. Based on this collaboration, the following habitat problems were identified: 1) Floodplain forest within the project area is of reduced quality. a. Includes limited species diversity in much of the area. b. Includes limited age diversity. 2) Reduced backwater fisheries overwintering habitat quality due to: a. Reduced depths due to sediment deposition. b. Reduced oxygen levels in McGregor Lake due to reduced water volume, Chemical Oxygen Demand and Biological Oxygen Demand, or other factors. c. Elevated water velocities, poor depth and/or reduced temperatures in other off-channel areas. 33

45 3) McGregor Lake may have inconsistent, limited or reduced SAV and EAV, including rooted floating plants) levels. This may be due to elevated turbidity levels, differences in substrate type, or other conditions. 4) Shoreline erosion is present on the perimeter of the project area. Erosion results in loss of floodplain forest habitat, reduced quality of main channel border habitat, and reduced quality of mussel habitat. Erosion is occurring at: a. The narrow peninsula that separates McGregor Lake from East Channel. Continued erosion could result in flows breaking through into McGregor Lake, accelerating sedimentation and further reducing seasonal backwater habitat values. b. Erosion on north side of the project area, downstream of where existing rock protection stops in the main channel, possibly in the east channel as well. RESOURCE PROBLEM: CONDITION AND LOSS OF FLOODPLAIN FOREST Floodplain forest in the UMR is dominated by a single species, silver maple. Many trees are the same age as well, due to initial impoundment which favored a sudden germination of certain species (e.g., silver maple) that have dominated the forest community for over 75 years. In many instances, LD operation has reduced the seasonal variability in water levels and prolonged inundation which has contributed to reduced species and age diversity. Healthy floodplain forests are critical for many nesting migratory birds. Loss of forest would reduce habitat quality for native wildlife that depend on floodplain forest. Within the project area, a few small areas of forest have excellent species diversity, while other large areas are primarily silver maple. RESOURCE PROBLEM: REDUCED QUALITY OF BACKWATER FISHERIES OVERWINTERING HABITAT. Backwater overwintering fisheries habitat is an important component of the UMR ecosystem. This type of habitat has declined with the processes of sedimentation and increased hydraulic connectivity reducing the number and quality off-channel areas that can be used by overwintering fish. Water quality and bathymetry within the project area suggest poor backwater overwintering habitat conditions. Field observations from fish sampling during latefall also confirm this observation. Within McGregor Lake, stressors include lack of deepwater habitat, and periodic low dissolved oxygen levels. Shallow depths can result in a lack of physical space as ice depths approach and exceed 2 feet in thickness. Lack of depth also results in lower total backwater volume, which over the course of winter limits the amount of DO available. This results in poor DO concentrations, particularly in late winter. Off-channel aquatic areas adjacent to McGregor Lake and north of the highway appear to experience elevated water velocities during the winter, resulting in low water temperatures. In many backwater locations depth is an issue. RESOURCE PROBLEM: LOSS OF EMERGENT AND SUBMERGENT AQUATIC VEGETATION Emergent and submergent aquatic plant communities are integral to habitat diversity in the UMR. Submergent and emergent vegetation has increased since 1975, but is still believed to be less abundant than optimal. Possible stressors include increased turbidity, activity of rough fish, and water levels that no longer are reduced to their low points during the late-summer low flow period. In the UMR, wetlands support a greater variety of amphibians and reptiles when they 34

46 are isolated from channels (Brenda Kelly, WDNR, pers. comm.). Many isolated wetlands have become more connected to the main channel and side channels since inundation due to erosion and higher water levels. RESOURCE PROBLEM: ISLAND EROSION Shoreline erosion identified above may threaten multiple habitat types. It could result in direct loss of floodplain forest and similar terrestrial habitat. It also could result in degraded main channel border habitat, including habitat used by the endangered Higgins Eye mussel. Erosion also threatens to result in two breaches in the existing natural levee around McGregor Lake. Such a breach would change habitat in McGregor Lake, including accelerated sedimentation and further loss of overwintering habitat PROJECT GOALS AND OBJECTIVES Because the project area is within the Upper Mississippi River National Wildlife and Fish Refuge, the Refuge management goals and objectives, the FWWG Desired Future Habitat Conditions, together with input from State and Federal agency natural resource managers, were used to guide the development of goals and specific project objectives. However, this study is only one part of a larger cooperative natural resource management effort on the river. The longterm effectiveness of any project will also depend on broader, system-wide management activities. Additional goals for the management of the Upper Mississippi River National Wildlife and Fish Refuge are documented in Appendix K: 2014 Problem Appraisal Report, Section 5. Earlier sections of this report discussed existing habitat conditions and problems. The habitat goals and objectives were developed as part of a coordinated effort on the part of all of the resource agencies involved in the study. The following factors were considered important in the development of the objectives: 1. Management objectives of the Upper Mississippi River National Wildlife and Fish Refuge (including the draft (2018) USFWS Habitat Management Plan for the Refuge), the Corps Systemic Forest Stewardship Plan, Fish and Wildlife Work Group, and the Wisconsin and IDNRs. 2. Historic and existing fish and wildlife habitat conditions. 3. Resource problems, opportunities, and constraints. 4. Habitat deficiencies, now and in the future for Pool Species groups and individual species habitat requirements. 6. Desirable hydraulic and sediment transport conditions to sustain habitat. Broad project goals are provided. Based on the project goals, specific objectives were then established. Many of these objectives are interrelated and will assist in meeting one or more of the four main goals. Criteria for habitat associated with each objective is also provided as target for design and measure of future success. It should be noted that not all criteria must be met in order to achieve the objective; the criteria are indicators of ideal conditions. FLOODPLAIN FOREST GOAL A: Increase age and species diversity of floodplain forest. Floodplain forest on the UMR is typically dominated by a few species that are a similar ageclass. This type of imbalance is generally unhealthy and leaves forest susceptible to invasive species. Forests have also become wetter over time, reducing the coverage of hardwood species and limiting the diversity of tree species. This project will aim to improve the quality and quantity (aerial coverage) of forest habitat. Restored floodplain forest will provide important 35

47 habitat for migratory and resident birds, and other wildlife such as aquatic mammals, turtles, and amphibians. Objective A Improve ecological health of floodplain forests. Habitat Target A: Optimize habitat conditions conducive to healthy floodplain forest habitat. Increase tree species diversity, ensure regeneration in aging forest stands, improve forest structure, and increase forest coverage. Increase coverage of lowland hardwood forest, characterized by oak species, hickory, and hackberry. Performance Criteria A. Within 50 years after project construction, achieve habitat for floodplain forest that is defined as: a. Overstory canopy cover 70 80% b. Overstory Species to include swamp white oak (Quercus bicolor), red oak (Q. rubra), bur oak (Q. macrocarpa) and hickory (Carya spp.). c. Basal area ft2 per acre d. Tree stocking 50% 90% e. Understory cover > 10 % f. Regeneration > 10% of area g. Coarse woody debris present h. Small cavities 2 visible holes per acre i. Den trees/large cavities 1 visible hole per 10 acres j. Invasive (herbaceous) < 10% k. Invasive (woody) < 10% Within 100 years after project construction, achieve these additional criteria: l. Emergent trees > 2 per acre m. Standing dead trees 2 large trees per acre LACUSTRINE HABITAT FOR BACKWATER FISH GOAL B: Improve and maintain protected lacustrine habitat for backwater species. Habitat conditions in the McGregor Lake area are considered suboptimal during the growing season and is limited in the winter for backwater fish species. Protecting and improving this habitat type is important as sedimentation and other processes has reduced the abundance of backwater overwintering habitat compared to historical conditions. Many species rely on this habitat type to survive over winter. Objective B Improve habitat quantity and quality for lacustrine species, including creation of discrete, overwintering habitat. The conceptual models developed as part of Upper Mississippi River System Ecosystem Restoration Objectives report (2009) provide a variety of recommendations on performance criteria for evaluating and planning lentic fish habitat restoration. The specific criteria were developed based on the experiences of State and Federal fishery biologists as to what would be desirable to provide suitable habitat for backwater fish species. Habitat Target B1: Increase aerial coverage of overwintering habitat areas. 36

48 Performance Criteria B1. Immediately after project construction, maintain existing overwintering areas, and create 1 or more overwintering sites. High quality overwintering areas should be less than 2 miles apart. Habitat Target B2: Improve habitat conditions conducive to overwintering habitat in backwaters during winter. Performance Criteria B2. Immediately after project construction, create overwintering sites defined as a combination of: a. Water depth greater than 7.4 feet (based on 80% exceedence during the growing season) in at least 50 percent of areas designated as overwintering habitat. b. DO levels as measured at mid-depth: Spring/summer/winter: greater than 5mg/l c. Water temperature (winter): 4 C 0 over 35 percent of the area, 2 to 4 C 0 over 30 percent of the area, 0 to 2 C 0 over 35 percent of the area. d. Winter current velocity less than 0.3 cm/sec over 80 percent of the backwater area. Habitat Target B3: Centrarchid abundance in constructed overwintering sites will increase and resemble that of known high quality sites. Performance Criteria B3: Within 10 years post-construction, restore/maintain lentic fish habitat to yield excellent fixed site electro-fishing catch per unit effort of age 1 plus fish in overwintering sites. Fair - Good: o 100 to 200 bluegills/hour o 50 to 100 largemouth bass/hour Good - Excel: o 200 to 300 bluegills/hour o 100 to 150 largemouth bass/hour Excellent: o More than 300 bluegills/hour o More than 150 largemouth bass/hour Habitat Target B4: Maintain habitat conditions conducive to meeting habitat needs of backwater fish assemblages for periods outside of the winter season. Performance Criteria B4. Maintain habitat conditions meeting needs for aquatic vegetation and substrate conditions for spawning: a. Access to substrates of sand and/or gravel available for spawning. b. Aquatic vegetation cover in the range of 40 to 60 percent (summer) and 25 to 50 percent (winter) in off channel areas. EMERGENT VEGETATION AND WETLANDS GOAL C: Increase emergent vegetation growth. Emergent Aquatic Vegetation is suboptimal and could be improved. EAV itself provides important plant diversity, and also adds ecological value given its use by fish and wildlife. 37

49 Objective C Increase emergent aquatic plant aerial coverage in the project area, with desirable density and species diversity. Habitat Target C: Create habitat conditions conducive to EAV. Performance Criteria C. Immediately after project construction, achieve habitat for emergent aquatic vegetation and emergent wetlands/mudflats that are defined as: Emergent Aquatic Vegetation: a. Less than 2 feet water depths for average river flows. b. Straight line wind fetch less than 3,500 feet for water depths of 2 feet. c. Secchi transparency greater than 0.8 meter on average during the June 1 - September 1 growing season in backwaters. d. Current velocities of 0.0 ft/sec is preferred; less than 0.2 ft/sec is acceptable under all but flood flows. Emergent wetlands/mudflats: a. Emergent wetlands located in proximity to land are optimal. b. Maintain and enhance microtopography within expanses of emergent wetlands/mudflats. c. Create small isolated wetlands by modifying islands. SUBMERGENT VEGETATION GOAL D: Increase submergent vegetation growth. Submergent Aquatic Vegetation is suboptimal; it provides important plant diversity, and adds ecological value given its use by fish and wildlife. Objective D Improve submergent aquatic plant density and species diversity. Habitat Target D: Create habitat conditions conducive to Submergent Aquatic Vegetation. Performance Criteria D. Immediately after project construction, achieve habitat for submergent aquatic vegetation defined as: a. Less than 5 feet water depths for average river flows. b. Straight line wind fetch of less than 6,000 feet for water depths of 3feet. c. Suspended sediment probability from wind wave action less than 60 percent. d. Secchi transparency greater than 0.8 meter on average during the June 1 - September 1 growing season in backwaters. e. Current velocities of 0.3 feet per second or less for all but flood flows. ISLAND EROSION GOAL E: Protect aquatic and terrestrial habitat by reducing erosion. Bank erosion is occurring at the upper end of the project area, as well as the natural levee that separates McGregor Lake and the east channel. This threatens backwater habitat by potential break thru flows, floodplain forest loss through erosion, and other habitat risks. This project will aim reduce erosion to protect these habitats. 38

50 Objective E Minimize land loss and protect backwater habitat and cultural resources. Habitat Target E: Minimize erosion at the upstream end of the project area, as well as the isthmus separating McGregor Lake and the East Channel, and the isthmus separating the lower southwestern corner of McGregor Lake and the adjacent side channel. Performance Criteria E: Terrestrial area within the project area is equal to or great than the terrestrial area in the 2010 land cover (398 acres) PLANNING CONSTRAINTS INSTITUTIONAL The McGregor Lake project area lies within the Upper Mississippi River National Wildlife and Fish Refuge and the State of Wisconsin. Refuge and State management goals and objectives must be complied with, as well as Federal, State and local laws and regulations. ENGINEERING Because of shallow water depths, access for construction equipment can be difficult in many areas without extensive dredging. Equipment restrictions and construction access will need to be considered in the planning and design of habitat restoration measures. In addition, substrate conditions and lake bottom sediments within McGregor Lake are extremely flocculent, more so than typical UMR backwaters. This presents additional stability challenges for constructing terrestrial features such as island or adjoining floodplain features, as well as dredging within the backwater. These stability concerns will need particular attention for any feature constructed away from shorelines and towards the middle of McGregor Lake. ENVIRONMENTAL The endangered mussel species Lampsilis higginsii is found in adjacent main channel and east channel areas. In fact, the entire project area is surrounded by waters identified as Higgins eye Essential Habitat Area by the USFWS. The threatened Northern long-eared bat may be present during the summer roosting period in the general project vicinity between April 1 and September 30. The threatened Eastern massasauga snake and the endangered rusty patched bumblebee could potentially be found in the project area, though there are no records of these species on the project site, and it is unlikely they are present. Project activities will need to consider potential impacts to these species. Although they are no longer listed as threatened under the Endangered Species Act, Bald Eagles are protected by the Bald and Golden Eagle Protection Act. Any project developed for the McGregor Lake area will need to avoid adversely affecting this species. In addition, construction of features within the floodplain could potentially impact flood conveyance and resulting flood stages. The project must minimize impacts to flood stages, otherwise appropriate permits may not be issued from the State of Wisconsin in support of construction. The threshold for modeled impacts to flood heights needs to remain below feet and thus will be considered a constraint for this project. CULTURAL Eleven archaeological sites have been identified within the McGregor Lake project area. One site, 47CR311, is listed on the National Register of Historic Places. Phase II archaeological 39

51 investigations identified site 47CR354 as eligible for listing, and site 47CR451 not eligible for listing (Stoltman & Theler 1980, Boszhardt 1982, Stoltman 2003, 2004, Scott 2010). Although additional investigations have not been completed on the remaining sites, the Corps considers these sites as eligible for listing on the NRHP. Therefore, the design of the project must be such that the project avoids or minimizes impacts on the archaeological sites. SOCIOECONOMIC/RECREATIONAL In developing ecosystem restoration measures and alternatives, it was assumed that Operation and Maintenance of the 9-Foot Navigation Channel would continue, including maintaining the impounded conditions and water regulation. No other specific socioeconomic constraints have been identified. The project area is between Prairie du Chien, WI; and Marquette and McGregor, IA. The project area, and in particular areas immediately adjacent, are heavily used by recreational boaters. Safety considerations will need to be given, but do not provide an immediate constraint. 4. POTENTIAL RESTORATION MEASURES A restoration measure is a feature (a structural element that requires construction or assembly on-site) or an activity (a nonstructural action) that can be combined with other management measures to form alternative plans. Management measures were developed to address problems in the project area and to capitalize upon opportunities. The following measures and combination of measures were formulated during scoping and discussion with stakeholders. This chapter presents the potential measures that were considered for implementation of the McGregor Lake HREP. The No-Action Alternative represents the conditions likely to occur with the continued execution of the current management in the project area POTENTIAL MEASURES Final measures outlined in the Final Problem Appraisal Report (PAR) were carried forward as the preliminary restoration measures for the Draft Feasibility Report. These were further refined by the Project Delivery Team (PDT) and agency partners through coordination. A brief discussion of alternative measures considered is described below. Additional information on the formulation of measures can be found in Appendix O Plan Formulation and Alternatives Analysis. No Action: The No-Action Alternative is defined as no implementation of a project to modify habitat conditions in the project area. The No-Action Alternative is synonymous with no Federal Action. The No Action Alternative is required under NEPA for comparison of proposed actions to a baseline condition. This will be carried forward. Floodplain Forest within McGregor Lake: This feature creates floodplain forest within McGregor Lake while also protecting the lake from flows from the main channel and the east channel. This includes using sand and dredged fine material to create new land areas raised to an elevation ideal for supporting desired tree species. Created floodplain areas would be planted with appropriate species to achieve a desired floodplain forest community. In a couple instances, rock protection would be needed in small areas to either protect newly constructed floodplain forest from erosion; or to allow flood flows to cross floodplain forest without impacts to flood conveyance. 40

52 Floodplain Forest Outside of McGregor Lake: Improves or creates floodplain forest in floodplain areas adjacent to McGregor Lake. Similarly, this uses sand, dredged fine material and tree planting to enhance or create floodplain forest. Dredging: Dredging will be used to collect fine sediment material needed for floodplain forest restoration, as well as enhance overwintering habitat for species in backwater areas. Wetland Features: Isolated wetland feature would be created through the placement of a rock berm set to elevation 615. This isolates aquatic areas allowing desirable SAV and EAV and associated biota to flourish. The wetland feature will be designed to be inundated about 50% of the years in the spring. Flow Modification Structures: This rock feature placed inside channel inlets would be designed to enhance the overwintering habitat by controlling the volume of flow entering aquatic areas during low flow periods. Erosion Protection: Riprap would be placed along river bank locations to prevent erosion and protect floodplain forest, aquatic or wetland areas, or other habitats. Consideration will be given to designing rip rap to function as habitat for native mussels. This could include the use of smooth stone, as opposed to chunk rip rap. Timber Stand Improvement (TSI): TSI is a non-structural measure that manages existing forest habitat to improve forest health and habitat quality. This can include thinning, planting, girdling, and invasive species removal. Measures Not Carried Forward from the PAR: Early in the feasibility phase, the project team quickly determined that two measures identified in the PAR for EAV and SAV would not be carried forward for detailed evaluation. Emergent Wetland/Mudflats is a measure that would use sand or fine material placement to raise lake-bottom elevations and create shallow water and mud flats for SAV and EAV. However, given the flocculent nature of backwater sediments and geotechnical concerns, particularly within McGregor Lake, this approach would likely not be effective. Small Scale Drawdowns are a measure that would involve periodic, seasonal drawdowns by blocking off a backwater, actively pumping water out to lower water elevations for several weeks and promote EAV and SAV. However, this measure would be expensive in most areas, and impractical on a backwater the size of McGregor Lake. It also has high risk within the project area given the variability in water elevations, and the potential a drawdown may not be successful due to a high-water event part-way through. Moreover, the benefits of drawdown are fairly short-lived (e.g., a few years) and the drawdown would need to be repeated to gain benefits across 50 years. For the above reasons, Emergent Wetlands/Mudflats and Small Scale Drawdowns were not carried forward. The wetland features identified above (rock structure to isolate wetlands) will be the measure considered for promoting EAV and SAV. Additional Measures Considered but Not Carried Forward: The project team evaluated the potential for removal of the old highway embankment north of the existing highway crossing. PDT evaluation included a site visit during May However, a number of issues quickly became apparent with embankment removal. First, while removal would help restore some habitat features, the benefits of such action appeared limited. Second, access to the site would prove difficult for removal. Third, the embankment includes a large amount of asphalt that is still on-site. Disposal of this asphalt would require additional expense due to contaminants. The measure also would likely not be compliant with USACE policy to address an issue with contaminated materials as a part of a habitat restoration project. Given the questions 41

53 with policy, likely high expense and limited benefits, this measure was eliminated from further consideration PLANNING CONSIDERATIONS River managers and engineers provided a number of ideas for consideration in the planning and design of project measures and alternatives. The Environmental Design Handbook (USACE 2012) also provides recommendations for consideration in planning and design of project measures. These recommendations were considered in planning and design for McGregor Lake, additional information can be found in Appendix O Plan Formulation and Alternatives Analysis 5. FEATURE EVALUATION & ALTERNATIVE PLAN FORMULATION Chapter 5 describes the formulation and evaluation process of project alternatives. Preliminary measures and combinations of measures were first evaluated through initial screening to identify a range of potential restoration alternatives that agency partners could support. Once a final range of project alternatives was identified, those alternatives were evaluated through an environmental benefit analysis to estimate ecosystem benefits expected if the features were implemented. The benefits were then combined with cost estimates for each feature and then a cost-effectiveness and incremental cost analysis (CE/ICA) was conducted to determine the optimal alternatives. Alternatives were generated by creating a range of possible combinations of the features that were carried forward. A full description of the environmental benefit analysis can be found in Appendix D Habitat Evaluation Procedures DEVELOPMENT OF ALTERNATIVES Project measures are any structural or nonstructural action that could address one or more of the planning objectives. Measures considered for this study are identified in Section 4.1. Alternatives were developed as combinations of these measures to protect, restore, and enhance habitat quality in the project area. Development of alternatives went through several iterations before the final array, described below, was agreed on by the Corps and resources agencies. A full discussion of the evolution of the potential restoration features and alternatives can be found in Appendix O Plan Formulation and Alternatives Analysis. While cost and environmental outputs must be considered, other factors such as the ability to construct, schedule, likelihood of achieving projected results, incidental benefits, professional judgment, and local support are also important for the selection of the preferred alternative. Floodplain Forest DEVELOPMENT OF ALTERNATIVES - PHASE 1 Preliminary measure and alternative formulation considered a wide range of potential options for habitat improvement. Because floodplain forest is an important habitat type under consideration for this project, and because of the influence of floodplain forest features on other measures, this planning effort formulated a range of floodplain forest combinations and structured its alternatives around those combinations. The project team considered a wide range of potential sites for forest restoration. Many were dropped from further consideration. These are outlined in Appendix O, but included areas both adjacent to and within McGregor Lake. Certain locations adjacent to McGregor Lake were 42

54 dismissed early by the project team because they already contained valuable wetland and transitional habitat. Additionally, the USFWS did not want to implement forest features in areas of existing forest that would require tree clearing. Conversely, creating islands for floodplain forest, and large shoreline floodplain forest within the eastern portions of McGregor Lake was dismissed for two primary reasons. First, large floodplain creation within eastern portions of McGregor Lake would impact flood conveyance potentially to the point that would preclude construction permits. Secondly, the extremely soft substrate of McGregor Lake would result in extreme subsidence of land features over time within McGregor Lake. While this could be accounted for through design and construction, it would require significantly more construction material (e.g., sand and fines) and thus have an increased cost, relative to the features recommended in the final list of alternatives. Preliminary analysis suggested that large floodplain forest features in McGregor Lake would be extremely expensive. It also would require more sand than is readily available from the UMR navigation channel maintenance program, which would then require the project to mine sand from the river in order to meet construction need. While floodplain forest construction in the eastern portion of McGregor Lake could impact flood conveyance, construction of floodplain forest in western portions of McGregor Lake, as well as areas immediately south of the highway embankment, would have less of an effect on flood flows. This provides a very unique opportunity to implement this type of habitat feature without impacting flood conditions. Hydraulic modeling was used to help understand these relationships and guide the layout of floodplain forest within project alternatives. With the above considerations, the project team identified seven locations for floodplain forest features. The basic design of floodplain forest at these seven locations went through several iterations to generally achieve a shape that provided desirable habitat and is believed to be constructible. The final shape and layout of these seven features is included at Plate 12 and Table 11. For the purpose of this feasibility analysis, these features will target an elevation of 620ft to achieve a desirable floodplain forest community. Each of these seven floodplain forest features could be combined in various ways to form the basic range of project alternatives, and were carried forward for detailed analysis. Dredging and Backwater Fisheries Habitat Backwater fisheries habitat in the project area, particularly overwintering habitat, is primarily limited by shallow water depths and poor habitat associated with these depths (e.g., poor dissolved oxygen and water temperature). Dredging of backwater areas to increase depths will subsequently improve habitat conditions. Backwater dredging also serves as the source of fine material to create the land features needed for floodplain forest. Given existing habitat conditions, the placement of dredged fine material would not be supported in the project area unless that material could be beneficially used for habitat. For this reason, the extent of backwater dredging was directly limited by the amount of fine material needed for various levels of floodplain forest created with each alternative. The project team identified several backwater areas for dredging (Plate 12 and Table 12). These areas were prioritized by the agency team. The project team determined that, given site conditions and proximity of these backwater sites to areas targeted for floodplain forest creation, the relative habitat benefits and costs of dredging each backwater would be relatively similar. Moreover, fine material obtained from McGregor Lake was the least desirable for construction given its more flocculent nature, and the depth of the extremely flocculent sediment layer. Fine material from the other backwater sites was preferable given it was less flocculent. As such, each backwater area would be dredged to a target depth of 7-8 feet deep. The highest priority areas would be dredged first, with subsequent backwaters dredged as more fine 43

55 material would be needed for each alternative. McGregor Lake would be the last location dredged to obtain fine material, but would provide whatever additional fine material would be needed to complete the needs for construction. Backwater dredging areas were not a consideration in the formulation of alternatives. However, the aquatic habitat benefits were captured as a part of each alternative analysis. Table 12 identifies which backwater areas would be dredged under each alternative. It should be noted that, given the high volumes of fine material generally needed, most alternatives would need to use all backwater sites identified. Erosion Protection Resource agency partners identified erosion as a major concern in the project area. As such, the project team identified several potential areas for erosion protection (Appendix O). These locations were screened based on preliminary cost estimates for each location, and the resulting habitat benefits as estimated in terms of habitat losses avoided over the next 50 years. In most cases, the cost of the rock was relatively high compared to the low levels of erosional losses prevented (e.g., average annual costs in excess of $10,000 per Average Annual Habitat Unit). The only stand-alone rock erosion protection recommended for detailed evaluation was the R4 feature on the main channel side of the project area, north of the existing highway embankment. This was carried forward for alternative formulation. Floodplain forest feature F14 requires an overflow spillway to protect the natural levee and control flows entering the north east end of McGregor Lake from the East Channel. Without this sill, flood flows would be directed around the newly constructed high ground, causing erosion in a new area. Therefore, the overflow spillway is considered an integral part of the functioning of F14 and not an independent project feature. Floodplain forest feature F15 requires rock protection along the side of the bank facing Honeymoon Slough. The flow from Honeymoon Slough would otherwise cause erosion of the newly construction forest feature, therefore, R2 is considered an integral part of F15 and not an independent feature. R2 will be constructed with round river-washed rock to provide some mussel benefits, though this is not its primary purpose. Additional Features Carried Forward The following features were small in scale, inexpensive to implement, but provided meaningful benefits for their size. These features were carried forward and included as a part of all floodplain forest alternatives formulated for detailed evaluation. Wetland Creation A single shallow aquatic area was identified for isolation to enhance submergent and emergent aquatic vegetation (Plate 12). This feature (W1) would be inexpensive to construct (approximately $135,000) and have relatively substantial benefits (about 9 Average Annual Habitat Units (AAHUs)). For this reason, W1 was carried forward and included as a part of all floodplain forest alternatives considered. Flow Control Structure A single flow control structure (C1) was identified for improving habitat conditions in Lovers Lane (Plate 12). This feature would be inexpensive to create (approximately $9,000) and augment benefits to 35 acres of aquatic habitat. The feature would reduce flows to ensure water temperature and velocity stay within recommended ranges during winter months to maintain overwintering habitat quality. For this reason, C1 was carried forward and included as a part of all floodplain alternatives considered. 44

56 Timber Stand Improvement TSI was identified as a non-structural management action that could be implemented to improve habitat conditions across a broad portion of the project area (Plate 12). The project area was reviewed and areas where TSI may be particularly effective were identified. This included approximately 35 acres, which would be inexpensive to implement (approximately $115,000, based on other recent HREP projects implementing TSI) for augmenting Floodplain Forest habitat. For this reason, TSI for 35 acres was carried forward and included as a part of all floodplain alternatives considered. Table 11. Phase 1 Measures for the McGregor Lake HREP Study that form the basis for alternative formulation. Note that F14 requires the inclusion of an overflow rock spillway; and F15 requires the inclusion of R2 erosion protection. Floodplain Forest Features F4b Floodplain Forest F8 Floodplain Forest F14 Floodplain Forest F15 Floodplain Forest F16 Floodplain Forest F16b Floodplain Forest F16c Floodplain Forest Erosion Protection Features R4 Erosion Protection Table 12. Project Features for the McGregor Lake HREP Study that Will Be Carried Forward and Included with Project Alternatives. Dredging areas are listed in priority order and will be used only to the extent needed to provide fine material for floodplain forest construction. Features W1, C1 and TSI are low-cost features that will be included with all alternatives. Dredging Area D4 Dredge Cut D5 Dredge Cut D6 Dredge Cut D9 Dredge Cut D7 Dredge Cut Additional Features W1 Wetland Habitat Feature C1 Flow Control Structure TSI Timber Stand Improvement DEVELOPMENT OF ALTERNATIVES - PHASE 2 The final array of alternative plans was developed by determining what measures were exclusive (could not be combined with other specific measures), dependent (needed another measure to physically function), and independent (could function on their own). The measures were then grouped into distinctively different feature groups for further evaluation. For the measures under consideration, none were exclusive. The Rock Protection measure (R4) could be considered independent. Floodplain forest features F8, F14 and F15 also could be considered independent. Conversely, it was assumed that F4b would not be constructed without F8, thus F4b is dependent on F8. Constructing floodplain forest F16 would be dependent on constructing F14, thus F16 is dependent on F14. Similarly, F16b would be dependent on 45

57 constructing F16; and constructing F16c would be dependent on constructing F16b. It also was assumed that F16b and F16c would only be constructed for alternatives involving the maximum amount of floodplain forest. Given the above considerations, the project measures were combined to form 39 different alternatives (Table 13). The list includes 19 different floodplain forest combinations both with and without the R4 rock erosion protection. This provided a broad range of alternatives in terms of both scale and cost. A No Action alternative also will be included. Table 13. Alternative Combinations for the McGregor Lake HREP Study Carried Forward for Detailed Analysis. All floodplain forest alternatives will include W1, C1 and TSI. Dredging areas are listed for each alternative and are only used to the extent needed to provide fine material for floodplain forest construction. The R4 alternative could be independent of all project features and was evaluated as its own alternative. All alternatives with F14 include an overflow rock spillway. All alternatives with F15 include rock shoreline protection (R2) dependent on that feature. Fine Material Location a Fine Material Location Alt # Measure Combination Alt # Measure Combination 1 F8 D4 21 F8+R D4 2 F8+F4B ALL 22 F8+F4B+R ALL 3 F15 D4 23 F15+R D4 4 F8+F15 D4 24 F8+F15+R D4 5 F8+F4B+F15 ALL 25 F8+F4B+F15+R ALL 6 F14 D4 + D5+D9 26 F14+R D4 + D5+D9 7 F8+F14 ALL 27 F8+F14+R ALL 8 F8+F4B+F14 ALL 28 F8+F4B+F14+R ALL 9 F16+F14 ALL 29 F16+F14+R ALL 10 F8+F16+F14 ALL 30 F8+F16+F14+R ALL 11 F8+F4B+F16+F14 ALL 31 F8+F4B+F16+F14+R ALL 12 F15+F14 ALL 32 F15+F14+R ALL 13 F8+F15+F14 ALL 33 F8+F15+F14+R ALL 14 F8+F4B+F15+F14 ALL 34 F8+F4B+F15+F14+R ALL 15 F16+F15+F14 ALL 35 F16+F15+F14+R ALL 16 F8+F16+F15+F14 ALL 36 F8+F16+F15+F14+R ALL 17 F8+F4B+F16+F15+F14 ALL 37 F8+F4B+F16+F15+F14+R ALL 18 F8+F4B+F16+F15+F14+ F16B ALL 38 F8+F4B+F16+F15+F F16B & F16C ALL R4 (R) None a All locations for fine material dredging include sites D4, D5, D6, D7 and D9. F8+F4B+F16+F15+F14+ F16B+R F8+F4B+F16+F15+F14+ F16B & F16C+R 5.2. EVALUATION AND COMPARISON OF FINAL ARRAY OF ALTERNATIVES This section describes the evaluation of the final array of alternatives including the potential costs and habitat benefits of each alternative. ENVIRONMENTAL BENEFIT ANALYSIS To quantify habitat benefits of the proposed alternatives, the USFWS Habitat Evaluation Procedure (HEP) was used (U.S. Fish and Wildlife Service 1980). The HEP methodology utilizes Habitat Suitability Index (HSI) models to rate quality of habitat on a scale of 0 to 1 (1 being optimal). The HSI value is multiplied by the number of acres of available habitat to obtain Habitat Units (HUs); the HSIs and acreages are then projected into the future. One HU is ALL ALL 46

58 equivalent to 1 acre of optimum habitat. HUs are then averaged annually across the project s 50- year period of analysis, referred to as Average Annualized Habitat Units (AAHUs). By comparing the AAHUs of the No-Action Alternative to each of the action alternatives, the benefits can be quantified (net gain in AAHUs). Based on the management objectives of the resource agencies in this portion of the river, wildlife bluebook models were used to quantify habitat benefits and evaluate effectiveness of the proposed measures. The Bluegill Overwintering HSI (Palesh & Anderson 1990) model was used to evaluate the aquatic habit. To quantify the floodplain forest, the black capped chickadee HSI (Schroeder 1983) and veery HSI (Sousa 1982) models were used. To quantify wetland benefits, the marsh wren HSI (Gutzwiller and Anderson 1987) model was used. To quantify the benefits from erosion protection, the king fischer HSI (Prose 1985) model was used. These models have been applied to other HREPs in the UMR and are certified by the USACE Ecosystem Planning Center of Expertise (ECO-PCX). A summary of the HEP results are provided in Table 14, focusing on the total lift, or gain, to each habitat type. For a detailed discussion of habitat analysis conducted for this study, see Appendix D Habitat Evaluation Procedures. Table 14. Habitat benefits by habitat type for each alternative. R4 protection benefits are habitat protection of an isolated wetland. Terrestrial benefits are attributed to floodplain forest and TSI. Aquatic habitat benefits are attributed to backwater dredging. Total Lift by Habitat Type (AAHUs) Alt # Combinations: R4 Protection W1 Wetland Terrestrial Aquatic Total Gain (AAHU) 1 F F8+F4B F F8+F F8+F4B+F F F8+F F8+F4B+F F16+F F8+F16+F F8+F4B+F16+F F15+F F8+F15+F F8+F4B+F15+F F16+F15+F F8+F16+F15+F F8+F4B+F16+F15+F F8+F4B+F16+F15+F14+ F16B F8+F4B+F16+F15+F14+ F16B and F16C R F8+R F8+F4B+R F15+R F8+F15+R F8+F4B+F15+R F14+R F8+F14+R

59 Total Lift by Habitat Type (AAHUs) Alt # Combinations: R4 Protection W1 Wetland Terrestrial Aquatic Total Gain (AAHU) 28 F8+F4B+F14+R F16+F14+R F8+F16+F14+R F8+F4B+F16+F14+R F15+F14+R F8+F15+F14+R F8+F4B+F15+F14+R F16+F15+F14+R F8+F16+F15+F14+R F8+F4B+F16+F15+F14+R F8+F4B+F16+F15+F14+ F16B+R F8+F4B+F16+F15+F14+ F16B and F16C+R COST EFFECTIVENESS & INCREMENTAL COST ANALYSIS Corps guidance requires a cost effectiveness analysis and incremental cost analysis (CE/ICA) to help make an informed decision on what project features and design alternatives provide the greatest value based on a comparison of quantified habitat benefits (outputs) and estimated costs of alternative designs. This process identifies which alternatives or combinations of features fully or partially meet the objectives of the project and at the same time are the most cost effective. A cost effective analysis is conducted to ensure that the least cost alternatives have been identified. Subsequent incremental cost analysis is conducted to evaluate changes in cost for increasing levels of environmental output. CE/ICA is a three-step process: (1) calculate the environmental outputs for each alternative; (2) determine a cost estimate for each alternative; (3) compare and evaluate the alternatives based on habitat benefits and costs. The IWR Planning Suite (IWR-Plan) tool was developed to aide environmental and ecosystem restoration planning studies in performing the CE/ICA on project alternatives. Costs were annualized 1 (AACost) over a 50-year period of analysis at an interest rate of 2.75% for Fiscal Year These costs included initial construction with mobilization and demobilization, contingency, planning, engineering, and design (10%), and construction management (10%) above the actual estimated cost for construction. Additionally, operation and maintenance ($2,000 per year for 50 years, based on recent O&M activities at similar UMR habitat projects targeting floodplain forest and backwater habitat), adaptive management 2 (3%), and interest during construction (assumed to be 3 years) were included in each alternative. The incremental analysis for each alternative was accomplished using the Corps Institute for Water Resources Planning suite. Further information on the analysis can be found in Appendix O Plan Formulation and Alternative Analysis. Primary assumptions and constraints used in conducting CE/ICA for the study are as follows: 1) AAHUs for all analyzed fish and wildlife species were assumed to have equal value in comparing alternative plans. 1 Average annual costs were derived by applying the capital recovery factor to the present value of the stream of project costs that are anticipated throughout the duration of the 50 year analysis period. 2 Adaptive Management activities and costs were derived from best professional judgment, consultation with Corps foresters and resource agency partners. 48

60 Of the 39 plans evaluated, 14 plans were considered Cost Effective, and nine were considered Best Buys, not including the No-Action Alternative. Cost Effective means that for a given level of non-monetary output, no other plan costs less, and no other plans yields more output for less money. Best Buys are the more efficient plans. The full array of alternatives and results of the CE/ICA analysis is displayed in Tables 15 and 16; and Figures 9 and 10. Table 15. Costs, Benefits, and Cost per Habitat Unit for All Alternatives. Alt # Feature Combination Construction Cost Total Avg. Annual Cost Total AAHU Gain AAC/ AAHU Cost Effectiveness 1 F8 $944,978 $39, $1,796 Best Buy 2 F8+F4B $8,418,375 $336, $5,915 No 3 F15 $2,004,978 $81, $3,453 No 4 F8+F15 $2,680,606 $108, $4,427 No 5 F8+F4B+F15 $10,154,003 $405, $6,152 No 6 F14 $4,991,187 $200, $2,711 Best Buy 7 F8+F14 $5,666,815 $227, $2,816 Best Buy 8 F8+F4B+F14 $13,140,212 $524, $4,717 Yes 9 F16+F14 $7,158,590 $286, $3,565 No 10 F8+F16+F14 $7,834,219 $313, $3,623 Yes 11 F8+F4B+F16+F14 $15,307,616 $610, $5,238 Yes 12 F15+F14 $6,726,815 $269, $3,361 No 13 F8+F15+F14 $7,402,444 $296, $3,503 No 14 F8+F4B+F15+F14 $14,875,840 $592, $5,165 No 15 F16+F15+F14 $8,894,219 $355, $4,098 No 16 F8+F16+F15+F14 $9,569,847 $382, $4,240 No 17 F8+F4B+F16+F15+F14 $17,043,244 $679, $5,659 No 18 F8+F4B+F16+F15+F14+ F16B $32,951,048 $1,310, $9,599 Yes 19 F8+F4B+F16+F15+F14+ F16B and F16C $51,058,755 $2,029, $14,597 No 20 R4 Only $671,262 $28, $5,542 Yes 21 F8+R4 $1,616,240 $66, $2,432 Yes 22 F8+F4B+R4 $9,089,637 $363, $5,850 No 23 F15 R4+R4 $2,676,240 $108, $3,755 Yes 24 F8+F15+R4 $3,351,869 $135, $4,550 Yes 25 F8+F4B+F15+R4 $10,825,265 $432, $6,078 No 26 F14+R4 $5,662,449 $226, $2,870 Yes 27 F8+F14+R4 $6,338,078 $253, $2,956 Best Buy 28 F8+F4B+F14 $13,811,474 $550, $4,735 Best Buy 29 F16+F14+R4 $7,829,853 $313, $3,661 No 30 F8+F16+F14 $8,505,481 $339, $3,708 Yes 31 F8+F4B+F16+F14+R4 $15,978,878 $636, $5,233 Best Buy 32 F15+F14+R4 $7,398,078 $295, $3,469 No 33 F8+F15+F14+R4 $8,073,706 $322, $3,597 Yes 34 F8+F4B+F15+F14+R4 $15,547,103 $619, $5,163 Yes 35 F16+F15+F14+R4 $9,565,481 $381, $4,157 Yes 36 F8+F16+F15+F14+R4 $10,241,110 $408, $4,289 Yes 37 F8+F4B+F16+F15+F14+R4 $17,714,506 $705, $5,638 Best Buy 38 F8+F4B+F16+F15+F14+R4+ F16B+R4 $33,622,311 $1,336, $9,433 Best Buy 39 F8+F4B+F16+F15+F14+R4+ F16B and F16C+R4 $51,730,018 $2,055, $14,255 Best Buy 49

61 Alt # Feature Groups Table 16. Results of CE/ICA for Best Buy Plans. Net AAHU Construction Cost a Inc. AACost AAHU Incremental Output Incremental AACost/AAHU - No Action 0 $0 $0 NA NA $0 $/AAHU 1 F $944,978 39, ,798 $1,796 6 F $4,991, , ,097 $2,711 7 F8+ F $5,666,815 26, ,952 $2, F8+F14+R $6,338,078 26, ,225 $2, F8+F4B+F14+R $13,811, , ,734 $4, F8+F4B+F16+F14+R $15,978,878 86, ,948 $5, F8+F4B+F16+F15+F14+R $17,714,506 68, ,700 $5, F8+F4B+F16+F15+F14+F16B+R $33,622, , ,245 $9, F8+F4B+F16+F15+F14+F16B+F16C+R $51,730, , ,546 $14,255 a Numbers have been rounded to nearest thousand. 50

62 Figure 9. Cost Effectiveness Analysis of All Alternatives. Figure 10. Best Buy Plans Incremental Cost and Output Results. 51

63 Comparison of the Best Buy plans provides information to assist with making a well-informed decision regarding desired project scale relative to incremental habitat output and cost. Progressing though the increasing levels of outputs for the alternatives in Table 16 helps determine whether the increase in outputs is worth the additional cost. As long as decision makers consider a level of output to be worth it, subsequent levels of output are considered. When a level of output is determined to be not worth it, then subsequent levels of output will also likely be not worth it, and the final decision regarding desired project scale and features for environmental restoration will be reached. COMPARISON OF BEST BUY ALTERNATIVES The following briefly describes the plan accomplishments of the Best Buy alternatives. No-Action. Within the CE/ICA analysis, the No Action is always a Best Buy alternative. This alternative was not chosen because it does not improve or maintain the ecosystem resources within the project area, and does not meet any of the project objectives. Alternative 1. This alternative includes constructing floodplain forest feature F8 (4.6 acres), along with dredging D4 (36 acres benefited). These backwater sites are necessary to obtain the amount of fines needed to construct F8. This provides a significant portion of the total aquatic benefits from this alternative. This alternative also includes W1, C1 and TSI as base features. This alternative at does not include erosion protection feature R4. This alternative would costs approximately $945,000 and provide a net gain of about 22 AAHUs throughout the project area, at an average annual cost of $39,566. This alternative was considered worth the investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest, and some level of erosion protection from future losses. This alternative does not include long-term protection of McGregor Lake via feature F14. It also includes the least amount of backwater dredged and aquatic habitat improvement. Alternative 6. This alternative includes constructing floodplain forest feature F14 (12.1 acres), along with dredging within D4, D5 and D9 (60 acres benefited). These backwater sites are necessary to obtain the amount of fines needed to construct F14. A key feature of F14 is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. This provides a significant portion of the total aquatic benefits from this alternative. This alternative includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative also includes W1, C1 and TSI as base features. This alternative does not include erosion protection feature R4. This alternative would costs approximately $5.0 million and provide a net gain of about 74 AAHUs throughout the project area, at an average annual cost of $200,280. This alternative was considered worth the investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest, and some level of erosion protection from future losses. Alternative 7. This alternative includes constructing floodplain forest feature F8 and F14 (16.7 acres), along with dredging in all backwater locations (72 acres benefited, with a small amount of additional dredging in McGregor Lake). These backwater sites are necessary to obtain the amount of fines needed to construct F8 and F14. A key feature with inclusion of F14 is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. This provides a significant portion of the total aquatic benefits from this alternative. This alternative includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative also includes W1, C1 and TSI as base features. This alternative does not include erosion protection feature R4. This alternative would costs approximately $5.7 million and provide a net gain of about 81 AAHUs throughout the project area, at an average annual cost of $227,153. This alternative was considered worth the 52

64 investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest, and some level of erosion protection from future losses. Alternative 27. This alternative is the same as Alternative 7, with the inclusion of erosion protection feature R4. This alternative would costs approximately $6.3 million and provide a net gain of about 86 AAHUs throughout the project area, at an average annual cost of $253,802. This alternative was considered worth the investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest. Alternative 28. This alternative includes constructing floodplain forest features F8, F4B and F14 (34.3 acres), along with dredging in all backwater locations (72 acres benefited, with additional dredging in McGregor Lake). These backwater sites are all necessary to obtain the amount of fines needed to construct the noted floodplain forest. A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. Alternative 28 includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative includes erosion protection with R4, as well as W1, C1 and TSI as base features. This alternative would costs approximately $13.8 million and provide a net gain of about 116 AAHUs throughout the project area, at an average annual cost of $550,685. This alternative was considered worth the investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest. Alternative 31. This alternative includes constructing floodplain forest features F8, F4b, F16 and F14, (41 acres), along with dredging in all backwater locations (72 acres benefited, with additional dredging in McGregor Lake). These backwater sites are all necessary to obtain the amount of fines needed to construct these floodplain forest features. A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. Alternative 31 includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative includes erosion protection with R4, as well as W1, C1 and TSI as base features. This alternative would costs approximately $16.0 million and provide a net gain of about 122 AAHUs throughout the project area, at an average annual cost of $636,802. This alternative was considered worth the investment but was less effective in meeting project objectives than other Best Buy alternatives, namely a reasonable maximization of floodplain forest. Alternative 37. This alternative includes constructing floodplain forest features F8, F4B, F14, F15 and F16 (45.2 acres), along with dredging in all backwater locations (72 acres benefited, with additional dredging in McGregor Lake). These backwater sites are all necessary to obtain the amount of fines needed to construct these floodplain forest features. A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. Alternative 37 includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative includes erosion protection with R2 and R4, as well as W1, C1 and TSI as base features. This alternative would costs approximately $17.7 million and provide a net gain of about 125 AAHUs throughout the project area, at an average annual cost of $705,753. This alternative was considered worth the investment and appears to best meet project objectives, including maximizing floodplain forest without substantial increases in cost. Alternative 38. This alternative includes constructing floodplain forest features F8, F4B, F14, F15 F16 and F16b (63.8 acres), along with dredging in all backwater locations (72 acres benefited, with additional dredging in McGregor Lake). These backwater sites are all necessary to obtain the amount of fines needed to construct these floodplain forest features. A key feature 53

65 of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. Alternative 38 includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative includes erosion protection with R2 and R4, as well as W1, C1 and TSI as base features. This alternative would costs approximately $33.6 million and provide a net gain of about 142 AAHUs throughout the project area, at an average annual cost of $1,336,788. This alternative meets project objectives, including maximizing floodplain forest. However, this alternative has a substantial increase in cost, relative to other alternatives. Alternative 39. This alternative includes constructing floodplain forest features F8, F4B, F14, F15 F16, F16B and F16c (84.3 acres), along with dredging in all backwater locations (72 acres benefited, with additional dredging in McGregor Lake). These backwater sites are all necessary to obtain the amount of fines needed to construct these floodplain forest features. In fact, this alternative results in the greatest relative percentage of McGregor Lake that would be dredged (greater than 70%). A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. Alternative 39 includes an overflow rock spillway as a part of F14 to assist with flood flow conveyance. This alternative includes erosion protection with R2 and R4, as well as W1, C1 and TSI as base features. This alternative would costs approximately $51.7 million and provide a net gain of about 144 AAHUs throughout the project area, at an average annual cost of $2,055,654. This alternative meets project objectives, including the maximum amount of floodplain forest of any alternative. However, this alternative has the most substantial increase in cost, relative to other alternatives, to maximize habitat benefits PLAN SELECTION Federal planning for water resources development was conducted in accordance with the Principles and Guidelines (P&G) adopted by the Water Resources Council. For ecosystem restoration projects, a plan that reasonably maximizes ecosystem restoration benefits compared to costs, consistent with the Federal objective, shall be selected. The selected plan must be shown to be cost effective and justified to achieve the desired level of output. This plan shall be identified as the National Ecosystem Restoration (NER) Plan. In addition, the concept of significance of outputs plays an important role in ecosystem restoration evaluation. The Corps Planning Guidance Notebook, ER E-37, explains this in detail. Along with information from cost effectiveness and incremental cost analyses, as well as information about acceptability, completeness, and effectiveness, information on the significance of ecosystem outputs will help determine whether the proposed environmental investment is worth its cost and whether a particular alternative should be recommended. Statements of significance provide qualitative information to help decision-makers evaluate whether the value of the resources of any given restoration alternative are worth the costs incurred to produce them. The significance of restoration outputs should be recognized in terms of institutional, public, and/or technical importance. Review of the four P&G criteria, resource significance, support from the resource agencies, and costs were used to aid in the selection of the Recommended Plan. Definitions of the P&G criteria and resource significance are described below. 54

66 P&G Criteria: Acceptable Acceptability refers to the workability and viability of the alternative with respect to acceptance by state and local entities and the public and compatibility with existing laws. Completeness Completeness is the extent to which the alternative plan provides and accounts for all necessary investments or other actions to ensure the realization of the planned effects. Effectiveness Effectiveness is the extent to which an alternative plan alleviates the specified problem and achieves the specified objectives. Efficiency Efficiency refers to cost-effectiveness and the most efficient allocation of other resources. Efficiency is the extent to which an alternative plan is the most costeffective means of alleviating the specified problem and achieving the specified objectives. Resource Significance: Institutional Recognition The importance of an environmental resource is acknowledged in the laws, adopted plans, and other policy statement of public agencies, tribes, or private groups. Public Recognition Some segment of the general public recognizes the importance of an environmental resource, as evidenced by people engaged in activities that reflect an interest or concern for that particular resource. Technical Recognition The resource qualifies as significant based on its technical merits, which are based on scientific knowledge or judgment of critical resource characteristics. Technical significance should be described in terms of one or more of the following criteria or concepts: scarcity, representativeness, status and trends, connectivity, limiting habitat, and biodiversity. PRINCIPLES AND GUIDELINES ALTERNATIVES SCREENING All of the Best Buy alternatives would be considered complete, in that no other action or investments would be required to achieve their respective output. All Best Buy alternatives would be considered acceptable as compatible with existing laws, regulations, and public policies. All action Best Buy alternatives are considered effective. However, some alternatives, particularly Alternative 37, 38 and 39, would provide a greater extent of forest habitat for priority species such as neotropical migratory birds, small mammals, amphibians, and reptiles. All action Best Buy alternatives are considered efficient, as by definition, they are the most efficient of the alternatives evaluated at providing benefits per unit of cost. RESOURCE AGENCY SUPPORT In general, the USFWS and the States of Iowa and Wisconsin support all of the Best Buy action alternatives. However, the natural resource agencies all preferred Alternative 37 over other alternatives. The resource agencies agree that this alternative maximizes opportunity for floodplain forest without the substantial cost increases that come with Alternatives 38 and

67 PROJECT COST The incremental cost between Alternative 31 and 37 is about $68,951, with the relative difference in the cost of construction of 10%. The additional 3.5 average annual habitat units gained as part of Alternative 37 would provide additional floodplain forest habitat (4 additional acres compared to Alternative 31), which is a primary management objective of the USFWS Refuge, and further improved the quality of overwintering habitat. The incremental cost to Alternative 38 is $631,035. Alternative 37 reasonably maximizes the ability to construct floodplain forest without impacts to flood heights, leverages use of channel maintenance sand to help keep restoration costs lower, and provides benefits to the channel maintenance program by beneficially using material. The Corps and resource agencies support the higher construction cost of Alternative 37 to gain the habitat improvements to floodplain forest and backwater aquatic habitat. The Corps and natural resource agencies fully agree that the high costs of alternatives 38 and 39 are beyond what could be reasonably be justified, even with the projected increases in additional forest habitat. RESOURCE SIGNIFICANCE All of the action Best Buy alternatives demonstrate institutional and public significance as they meet goals and objectives of the Upper Mississippi River National Wildlife and Fish Refuge and the multi-agency coordination effort in maintaining a high quality UMR ecosystem while avoiding adverse impacts. Review of technical importance for the best buy alternatives considered to be worth the investment supported the selection of Alternative 37. Technical review can best be demonstrated using six criteria: scarcity, representativeness, status and trends, connectivity, limiting habitat, and biodiversity. Scarcity: Deep off-channel habitat and highly diverse forests that provide diverse floodplain forest habitat have become rare in the UMR floodplain. All the action alternatives would help to reduce the scarcity of these habitat types to varying degrees. Alternative 37 provides an additional 4 acres of floodplain forest habitat compared to Alternative 31. It is able to do this without impacts to flood conveyance, which is unusual for floodplain forest construction on the UMR. This is because large portions of floodplain forest restoration would be within the hydraulic shadow of the upstream highway embankment. It also requires enough fine material to be dredged from McGregor Lake that flood flow conveyance through the lake is maintained. Sediment deposition over the next 50 years would be reduced enough that dredging features should be effective for the project life. Representativeness: The conditions created through the action alternatives would promote the presence of a large number of native tree species and would help to promote desired forest conditions in the project area. This would include the acreage of created forest, plus acreage benefited via Timber Stand Improvement. Alternative 37 reasonably provides the greatest amount of forest habitat relative to any other alternative worth the investment. It also broadly improves backwater fish habitat. Status and Trends: There is little recruitment in the understory of the floodplain forest in the UMR floodplain and a significant decline in forest canopy is 56

68 expected to occur in the next 50 years. Alternative 37 would provide habitat conditions that increase the likelihood of a sustained forest canopy. The resource agencies have documented the sharp decline in overwintering fish use of the UMR over the last several years. Increased velocities and loss of depth due to sedimentation are the primary causes. Alternative 37 would improve habitat conditions in McGregor Lake and adjacent backwaters. Connectivity: Alternative 37 provides reasonably more floodplain forest habitat than other alternatives. These forested areas are important for some wildlife, including migrating birds that forage the UMR bottomland forests to refuel along their long journeys. The configuration of suitable foraging habitat can help improve their health and fitness by allowing them to expend less time and energy moving across patches that are unsuitable for foraging (Simons et al. 2000, Pearson and Simons 2002). Similarly, backwater overwintering habitat should be available every few miles of river corridor to maximize potential for fish populations. Alternative 37 helps to provide backwater fish habitat within a reach that has limited overwintering habitat under existing conditions, and where such habitat would be further reduced or absent all together in the future without the project. Limiting Habitat: Both quality floodplain forest habitat, and deep off-channel habitat are limited in the UMR. Forrest habitat is used by a wide range of wildlife resources, including unique species such as nesting neotropical migrants. The deep off-channel habitat allows several fish species a suitable place to conserve energy in the winter months. Alternative 37 makes these habitat types available to the greatest extent of any of the best buy plans considered to be worth the investment. Biodiversity: Alternative 37 would be likely to reasonably increase the species richness of floodplain trees and associated forest wildlife to the greatest extent of any of the alternatives. This is because Alternative 37 includes larger amount of forest habitat that provide key habitat conditions lacking from smaller forest areas. The elevation of the forest constructed under Alternative 37 would support a number of tree species that are currently limited within the project area, many of which have been shown to be preferred foraging species by songbirds in the UMR (Wood et al. 2012). RECOMMENDED PLAN The McGregor Lake PDT determined that Alternative 37 is the plan that best meets the goals and objectives of each agency and the UMRR program, and was chosen to be the Recommended Plan (Figure 11 and Plate 13). This alternative includes constructing floodplain forest features F8, F4B, F14, F15 and F16 (45.2 acres) through the use of sand and fine material placement up to a maximum elevation of 620 ft. Sand material will come from channel dredging associated with the channel maintenance program. Fine material will come from dredging all identified backwater locations (Plate 13; approximately 250 acres of aquatic habitat benefited). A key feature of this alternative is that it provides long-term protection of McGregor Lake to degradation from break through flows from the East Channel. This accomplished via Floodplain Forest feature F14. The recommended plan includes erosion protection with R4. It also includes emergent wetland feature W1, benefiting about 21.5 acres of emergent wetland; flow control structure C1; as well as TSI for existing floodplain forest areas. 57

69 Figure 11. McGregor Lake HREP Recommended Plan. NATIONAL ECOSYSTEM RESTORATION PLAN The alternative plan that reasonably maximizes the benefits in relation to cost and meets the overall planning objectives is Alternative 37, which was selected as the National Ecosystem Restoration Plan (NER Plan). When viewed relative to the preliminary costs of similar ecosystem restoration projects, the $5,638 per AAHU created by Alternative 37 is efficient in achieving the ecosystem restoration objectives and has been considered reasonable for recent 58

70 past HREPs within the UMRR Program. The Recommended Plan is supported by the USFWS, and is consistent with regional and State planning for the area (letter of support to will be provided and documented in Appendix A Correspondence once obtained). At this stage in planning HREPs, yielding an average annual cost per AAHU of over $8,000 have recently been accepted as justified. The Federal objective for water and related land resources planning is to contribute to national economic development consistent with protecting the Nation s environment, pursuant to national environmental statutes, applicable Executive Orders, and other Federal planning requirements. Achievement of the Federal objective is measured in terms of contribution to Federal accounts intended to track the overall benefits of a given project. The two accounts most applicable to the McGregor Lake HREP are the National Economic Development (NED) account and the Environmental Quality (EQ) account. Regional Economic Development (RED) and Other Social Effects (OSE) are other accounts used for display in Ecosystem Restoration Projects in accordance with ER Other Social Effects, if any, would be similar among the alternatives and would not contribute to a decision among the alternatives. Regional Economic Development (RED) Account: The RED account is intended to illustrate the effects the alternatives would have on regional economic activity, specifically, regional income and employment. While a detailed regional economic development analysis was not performed for the Recommended Plan or other alternatives, it is generally accepted that the ecosystem restoration projects that are part of the HREP have contributed RED benefits in small ways as each project is constructed. Over a longer term, ecosystem restoration projects contribute to RED benefits on a larger scale by creating added eco-tourism opportunities and increasing economic opportunities in local communities along the entire UMRS. HREP, through its 29-year history, has created thousands of employment opportunities related to HREP planning, construction, and evaluation; Long Term Resource Monitoring (LTRM) and research. Once completed, habitat projects create new or improved outdoor recreation opportunities, further stimulating local and regional expenditures. Other Social Effects (OSE) Account: The OSE account is intended to illustrate the effects the alternatives would have on lives of residents and the social fabric of communities in the project area. The OSE account assists in plan formulation and in choosing an alternative that maximizes social benefits. Ecosystem restoration projects such as this one typically have positive net effects on the OSE account. Quality of life variables such as health and safety, material wellbeing, and social connectedness are improved as a result of HREPs. While the increment may be slight or difficult to measure for any individual HREPs, taken as a whole, the numerous completed restoration projects over 30 years of the HREP program have greatly enhanced social factors in the UMRS. National Economic Development (NED) Account: Contributions to NED are increases in the net value of the national output of goods and services expressed in monetary units. NED recreation benefits for projects that increase the supply of recreational facilities are measured as the willingness to pay for the increment of added supply. To the extent that the selected NER Plan, Alternative 37, provides additional recreation opportunities or improves upon existing ones that users would be willing to pay, it contributes to the NED account. Recreation facilities associated with Alternative 37 are not considered sufficient to warrant additional analysis and quantification of willingness to pay. Therefore, recreation benefits have not been quantified for this study. Environmental Quality (EQ) Account: The EQ account measures effects on ecological, cultural, and aesthetic resources. For ecosystem restoration projects such as this one, contributions to the EQ account are detailed both through NEPA compliance and through calculation of net ecosystem benefits. Here, NEPA compliance is achieved by integrating an EA 59

71 into this feasibility report, with a qualitative summary of environmental effects detailed in Table 17 as well as in Chapters 6 and 7 of this report. A calculation of net ecosystem benefits was completed through the use of HEP and HSI models. The quantitative results of the evaluation are contained in Appendix D. The credit for the EQ account is the quantified benefits resulting from the project, which in the case of the Recommended Plan, provides a net gain of 125 AAHUs over the 50-year period of analysis. RISK AND UNCERTAINTY Areas of risk and uncertainty have been analyzed and were defined so that decisions could be made with some knowledge of the degree of reliability of the estimated benefits and costs of alternative plans. Risk is defined as the probability or likelihood for an outcome. Uncertainty refers to a lack of knowledge about critical elements or processes contributing to risk or natural variability in the same elements or processes. Various risks exist with construction of this project. These include variability in the volume of sand available from the channel maintenance program; potential variability in the amount of subsidence projected for floodplain forest features (and the amount of sand needed for base construction); and the ability to work with the large volume of fines needed for floodplain forest construction. There are risks associated with achieving the desired outcomes of the project. These risks include stochastic events such as large flood events that could cause widespread mortality to the planted floodplain forest. In addition, there is some uncertainty on performance of the features due to the many interacting variables that contribute to habitat function. The team worked to manage risk in developing measures. Measures were developed using the Construction Design Handbook, referencing similar HREPs and best professional judgment. The team used experience from past projects to identify potential risks and reduce uncertainty during plan formulation. Risk would be minimized by proper design, appropriate selection, and correct seasonal timing of applications. Risk also would be managed by incorporating flexibility into project design and contract award. This will give contractors the ability to use different methods to work with the large volumes of fine material needed. Flexibility also will help account for potential differences in the quantity of sand available for construction; or if increased settlement rates requires higher sand volumes. In the event that sand availability becomes an issue (either due to lower channel maintenance dredging; or greater sand volumes are needed due to high feature settlement), project features could be modified to reduce feature size, including project footprint shape. These modification could be done to moderate levels without substantially impacting anticipated benefits from the project. Post-construction monitoring and adaptive management (Appendix P) would be used to identify and address issues with feature performance and habitat response. CONSISTENCY WITH CORPS ENVIRONMENTAL OPERATING PRINCIPLES The Corps has reaffirmed its commitment to the environment by formalizing a set of Environmental Operating Principles (EOP) applicable to all of its decision-making and programs. The formulation of alternatives considered for implementation met all of the EOP principles. The EOPs are: foster sustainability as a way of life throughout the organization; proactively consider environmental consequences of all Corps activities and act accordingly; create mutually supporting economic and environmentally sustainable solutions; continue to meet our corporate responsibility and accountability under the law for activities undertaken by the Corps, which may impact human and natural environments; consider the environment in employing a risk management and systems approach throughout the life cycles of projects and programs; 60

72 leverage scientific, economic and social knowledge to understand the environmental context and effects of Corps actions in a collaborative manner; and employ an open, transparent process that respects views of individuals and groups interested in Corps activities. The EOPs were considered during the plan formulation and the Recommended Plan is consistent with the EOPs. The Recommended Plan promotes sustainability and economically sound measures by incorporating the most natural and least cost methods for restoring habitat for fish and wildlife species. 6. ENVIRONMENTAL CONSEQUENCES Chapter 2 identified the existing conditions of the resources for the McGregor Lake HREP project area. Chapter 6 describes the environmental consequences of the alternatives considered compared to the no-action FWOP condition. The depth of analysis of the alternatives corresponds to the scope and magnitude of the potential environmental impact. This chapter provides the scientific and analytic basis for the comparison of alternatives and describes the probable consequences (impacts and effects) of each alternative on the selected environmental resources. The purpose of characterizing the environmental consequences is to determine whether the resources, ecosystems, and human communities of concern are approaching conditions where additional stresses will have an important direct, indirect, or cumulative effect (CEQ 1997). The Recommended Plan (Alternative 37) and the No-Action Alternative are the primary actions evaluated discussed in this section. Due to the integrated format of this document, the benefits of the alternatives were assessed in the previous section (Section 5) through the development, evaluation, and selection process. Therefore, only the effects of Recommended Plan and No- Action Alternative are discussed in detail below. Summary of Consequences: The Recommended Plan would result in positive long-term benefits to floodplain forest, aquatic habitat, and isolated emergent wetland habitat in and around the McGregor Lake project area. The project would result in some conversions of cover types, but the resulting changes would provide habitat to a greater diversity of species. No federally protected species would experience significant negative effects. Construction of the project would cause short-term adverse effects to water quality, air quality, aesthetics, wildlife habitat, and public use. Long-term benefits to habitats would far outweigh the short-term impacts. No significant negative social or economic impacts would result. No historic properties are anticipated to be adversely impacted by the proposed action. Environmental consequences of the proposed action are summarized in Table Alternative Table 17. Environmental Assessment Matrix for Proposed Project. Section 122 of the River and Harbor and Flood Control Act of 1970 (PL ) Recommended Plan No Action (Alternative 37) BENEFICIAL a ADVERSE b BENEFICIAL a ADVERSE b PARAMETER A. SOCIAL EFFECTS 1. Noise Levels X ST - 2. Aesthetic Values X X ST 3. Recreational Opportunities X X ST 4. Transportation X X 5. Public Health and Safety X X 6. Community Cohesion (Sense of Unity) X X 61

73 Section 122 of the River and Harbor and Flood Control Act of 1970 (PL ) Alternative No Action Recommended Plan (Alternative 37) BENEFICIAL a ADVERSE b BENEFICIAL a ADVERSE b 7. Community Growth & Development X X 8. Business and Home Relocations X X 9. Existing/Potential Land Use X X 10. Controversy X X B. ECONOMIC 1. Property Values X X 2. Tax Revenue X X 3. Public Facilities and Services X X 4. Regional Growth X X 5. Employment X ST 6. Business Activity X ST 7. Farmland/Food Supply X X 8. Commercial Navigation X X 9. Flooding Effects X X 10. Energy Needs and Resources X X C. NATURAL RESOURCE EFFECTS 1. Air Quality X ST 2. Terrestrial Habitat X X ST 3. Wetlands X X ST 4. Aquatic Habitat X X ST 5. Habitat Diversity and Interspersion X X ST 6. Biological Productivity X X ST 7. Surface Water Quality X X ST 8. Water Supply X X 9. Groundwater X X 10. Soils X ST 11. Federally-Listed Threatened or X X Endangered Species D. CULTURAL RESOURCE EFFECTS 1. Historic Architectural Values X X 2. Pre- & Historic Archeological Values X X a Beneficial: +++ = significant; ++ = substantial; + = minor. b Adverse: --- = significant; -- = substantial; - = minor. 0 = No effect. X = Long-term effects; ST = Short-term effects NATURAL RESOURCES FLOODPLAIN FOREST HABITAT Impacts of the No-Action Alternative: With no action, the floodplain forest habitat will decline. Areas in F8 and F4 that are currently showing signs of stress will continue to decline. The majority of the floodplain forest canopy within the project area (85%) is a single species 62

74 silver maple. A monoculture makes a plant community vulnerable to insects and diseases. If a major pathogen, such as Dutch elm disease or emerald ash borer, were to impact silver maple, the majority of the floodplain could transition from native forest cover to invasive herbaceous cover, such as reed canary grass. While it is impossible to predict the occurrence of this kind of disturbance, lack of species diversity leaves the forest without resiliency to these stochastic events. In addition, the project area lacks the total acreage of floodplain forest that once existed on the floodplain. Many acres of forest were lost to inundation, creating a lack of high quality habitat for terrestrial wildlife. With no action, the forest will continue to experience substantial adverse effects on the habitat quality. Impacts of the Recommended Plan: The recommended plan will create about 39 acres of new floodplain forest, restore about 6 acres of existing floodplain forest by raising the elevation, and restore 35 acres of existing floodplain forest through timber stand improvement. Approximately one acre of floodplain forest will be removed to access the D5 dredge area. The removed material will be used to construct floodplain forest elsewhere. Therefore the impact to the habitat will be a temporary minor adverse effect in that location. There will also be a temporary minor adverse effect at F14 where some of the existing forest will be cleared for access and staging. The 45 acres of new and raised floodplain forest will be flooded less frequently than other areas of the floodplain, restoring the natural hydrology of the preinundation forest condition. This flood regime closely mimics high quality natural floodplain nearby that continues to support a diverse mix of tree species. This project restores the functional characteristics of the floodplain forest, which will result in a more resilient forest for decades to come. Diverse tree and shrub mixtures will be planted and seeded onto both the new and existing forest areas. Increased species diversity is extremely important for forest resilience and provides a rich and varied habitat for wildlife. Floodplain forest has been identified as one of the most critical resources by multiple agencies, and this plan provides a substantial beneficial effect on the forest habitat quantity and quality. AQUATIC RESOURCES Impacts of the No-Action Alternative: In the no action alternative, the aquatic habitat will continue to decline. There is only one notable overwintering site in the project area, near the proposed D6 dredge area. McGregor Lake provides some limited overwintering habitat, but the breakthroughs in the northeast and southwest corners will eliminate the overwintering value of the lake in the next decade. Sedimentation is occurring at approximately 0.5 cm per year, slowly decreasing depths throughout the project area, and areas that provide both lentic habitat will decline. In addition, wetland habitat will decline at the location of the breakthrough described above. The isolated wetland will become connected to the main channel, increasing sedimentation and turbidity and favoring invasive species. Impacts of the Recommended Plan: The recommended plan improves five overwintering sites in the project area benefiting over 250 acres of aquatic habitat. These sites are distributed throughout the project area and provide a diversity of sites for fish to utilize. The flow modification structure at C1 will ensure that high flows do not negate the overwintering habitat that occurs at D4 under existing conditions. A small area of mussel habitat will be created along the rock protection that is a required feature of F15 in the southwest side of McGregor Lake. Isolated wetland habitat will be protected with the R4 features and will be created with the W1 feature. These two features will provide higher quality wetland habitat than would occur under the no-action alternative. During construction there would be some minor short-term adverse effects to aquatic habitat and wetlands due to temporary sediment suspension, rock placement, and construction activity. The recommended plan will provide a substantial long-term beneficial effect on aquatic habitat quantity and quality. 63

75 HABITAT DIVERSITY AND INTERSPERSION Impacts of the No-Action Alternative: Under the no-action alternative, there would be substantial loss of habitat diversity. Floodplain forest will decline in diversity, leading to more homogenous forest types. Shallow backwater areas will fill with sediment, loosing topographic diversity of deeper sites. The isolated wetland at R4 would become more connected to the main channel, which would transform it into another very connected backwater, of which there are many in the area. With the decline in habitat diversity, the interspersion of the habitat will also decline as the habitat becomes more homogenous. The aquatic areas will become shallower and have fewer deep sites. Habitat interspersion will substantially decline. Impacts of the Recommended Plan: The recommended plan will substantially improve habitat diversity and interspersion. Ridges of high-elevation, diverse forest will be interspersed with lower-elevation, wetter forest. Deep overwintering backwater sites will be interspersed with shallower aquatic habitat. Isolated wetlands will be interspersed among forested and open water areas. Importantly, the habitat diversity will be enhanced with the two isolated wetland sites (W1 and R4) and the new higher forest areas. GEOLOGY AND SOILS Impacts of the No-Action Alternative: The no-action alternative would not disturb any soils. There would be no impact. Impacts of the Recommended Plan: The proposed alternative would have a temporary minor adverse effect on geology and soils. Dredging in D5 may destabilize the banks in a few areas that are very narrow and require steep slopes. Engineering analysis indicates that these slopes will likely remain stable, however, there is a slight chance for sloughing and bank erosion to occur in this area. In the constructed floodplain forest, there would be temporary adverse effect on the dredged sand and fine material that is used to construct new land. Over time, this substrate will develop soil characteristics that support vegetation. Soils may be disturbed as material is placed along the natural shoreline. These effects will be temporary and minor. Soils in the TSI forest stands will have minor short-term disturbance when trees are planted. WILDLIFE Impacts of the No-Action Alternative: In the no action alternative, wildlife would be adversely impacted by declining habitat. Terrestrial and aquatic habitat would continue to decline, as described above. Impacts of the Recommended Plan: The recommended plan would result in short-term minor adverse effects to wildlife as animals would leave the area during construction due to activity and noise. After construction, wildlife would return. The recommended plan would result in substantial long-term beneficial effects for wildlife due to habitat improvement. FEDERALLY-LISTED THREATENED AND ENDANGERED SPECIES Section 7 of the Endangered Species Act generally requires Federal agencies to insure that any action authorized, funded or carried out by the agencies are not likely to jeopardize the continued existence of any endangered species or threatened species or result in the destruction or adverse modification of habitat of such species (16 USC 1536(a)(2)(1988)). The USFWS s Information Planning and Conservation (IPaC) website consulted in May 2018 to identify federally-listed threatened or endangered species known to occur within the Project Area. Several federally-listed threatened or endangered species, listed in Table 7 have the potential to occur within the Project Area. 64

76 Impacts of the No-Action Alternative: The no action alternative would have no effects on federally-listed threatened or endangered species. Impacts of the Recommended Plan: The recommended plan would have no effect on most threatened or endangered species, and may adversely affect but will not cause prohibited take of the northern long-eared bat. As described previously, the main channel and East Channel surrounding the project area are an Essential Habitat Area for the Higgins Eye pearlymussel. The other two endangered mussels listed for Crawford Co, WI are sheepnose and spectaclecase. Mussel surveys have been completed in many areas, including for all project features, and in the surrounding channels. The sheepnose and spectaclecase mussels are very rare and have not been found in the recent mussel surveys in the area. The recommended plan will not affect the Higgins Eye. The USFWS maintains an online map that displayed high and low potential zones for the rusty patched bumble bee (accessed May 2018). Figure 12 and Figure 13 show the high and low potential zones near the project areas. There is a high potential zone to the east of the project area and a low potential zone that includes the project area. A low potential zone mean that the area is within the species maximum dispersal potential from known sites. The species could theoretically be present but is not likely to be present in the low potential areas. Section 7 consultation and incidental take permits are not necessary for projects in low potential areas. There is extremely low probability that this species is currently found on the project site. At present, the project area does not provide the prairie habitat that the bee prefers. There are very few plants on the project site that would provide food sources. The recommended project could have a minor short-term beneficial effect on the species, but this is unlikely. When the new floodplain forest is planted, native prairie plants will be planted to provide temporary cover on the site before the tree canopy matures. During the early stages of the project, these plants could provide habitat for the bumble bee, though it is unlikely the bee would use the habitat since most of the area is flooded each year, making it unsuitable for nesting. Figure 12. Rusty Patched Bumble Bee Potential Zones. 65

77 Figure 13. Rusty Patched Bumble Bee High Potential Zones. The federally-listed threatened eastern massasauga uses a variety of wetland habitats, including wet meadows, marshes, and floodplain forests. Past reptile surveys within the project area have not recorded this species on the project site. There are no records of the species within the project area (Brenda Kelly, WDNR, pers. comm). During construction, if any individuals are observed, construction will be halted and the USFWS will be consulted. Because the island complex is not adjacent to uplands, the likelihood of encountering a massasauga in the area is very low, there will be no effects. The whooping crane is an experimental non-essential species. There will be no adverse effect on this species. Due to the fact that the proposed work would involve tree removal, consultation from the USFWS will be required for the northern long-eared bat through a rule under Section 4(d) of the Endangered Species Act, 16 U.S.C. 1533(d). The Corps will provide the USFWS information regarding Northern long-eared bats and the proposed project through the Section 4(d) Rule Streamlined Consultation Form after project design is completed. During project design, the precise number and location of trees to be removed for access and staging will be determined. This will allow a more detailed evaluation of potential impacts to the bat than possible during feasibility. In addition, the 4(d) form will be used to consult regarding potential impacts that would be caused by TSI work. TSI work will occur coincident with tree planting on the completed constructed forest area. Since the forestry work will occur separately from the main construction and will occur after the major construction work, consultation on effects to the northern long-eared bat will occur closer to the implementation of that work, allowing for both more accuracy of the tree removal and more updated information on the bat status. The project will utilize Best Management Practices (BMPs) to minimize bat impacts, such as removing trees during the winter when bats are hibernating. Therefore, any adverse effects to the bat would be minor. The Bald and Golden Eagle Protection Act prohibits anyone from taking, possessing, or transporting an eagle, or the parts, nests, or eggs of such birds without prior authorization. Disturbing an eagle to a degree that causes, or is likely to cause injury to an eagle, decrease productivity, or cause nest abandonment are considered forms of take. Activities that directly or indirectly lead to take are prohibited without a permit. 66

78 Several bald eagle nests are located in the project area, shown in Plate 11. The USFWS recommends maintaining a buffer of at least 660 feet between project activities and active eagle nests. However, the location of some project features is within the 660 feet of a nest. To ensure take is avoided, construction within 660 feet would be delayed each year until eagle chicks have fledged (likely by mid-june) and/or assistance from USFWS staff would be used to monitor eagle behavior during construction activities. WISCONSIN AND IOWA STATE LISTED SPECIES Impacts of the No-Action Alternative: With no action, the habitat would continue to decline. The WI and IA DNRs have indicated the backwater habitat is limited for state-listed species. These species would be impacted by the loss of protected backwater habitat as the two breakthroughs bring more flow into McGregor Lake. State-listed frogs and turtles may be impacted by erosion into isolated wetlands. Impacts of the Recommended Plan: The recommended plan would improve habitat for state-listed fish, birds, frogs, and turtles, as described in the sections on floodplain forest and aquatic resources. There would be a minor beneficial effect on these species. There may be short-term minor impacts to state-listed species. Fish and mussels may have minor adverse impacts due to the placement of material for forest construction. Birds and mammals will temporarily vacate the construction area. Bats may be impacted by the removal of trees for construction or TSI activities. Frogs and turtles may be impacted by forest construction and rock placement for wetland protection and creation at R4 and W1. However, these effects will be short-term. Long-term all these species will be impacted beneficially due to habitat improvements. Turtles and frogs will benefit from higher quality wetlands. Birds and mammals, including bats, will benefit from more diverse and resilient forests. Fish and mussels will benefit from deeper backwaters, protected channel banks, and rock substrates for cover. Overall, the impacts to state-listed species will include minor short-term adverse impacts and substantial beneficial long-term impacts. FISHERIES Impacts of the No-Action Alternative: The backwater overwintering habitat in the project area has, for the most part, disappeared due to increased flow and sedimentation. However, there are still some small areas that do provide marginal overwintering habitat when conditions are just right. As flow and sedimentation increase, the availability and quality of this marginal habitat will continue to decline. Impacts of the Recommended Plan: The recommended plan would have a beneficial effect on lentic fish populations. The habitat dredging would provide depth and protection from flows, conditions that have diminished in the project area in recent years. These conditions would provide winter refugia for several backwater species of fish, increasing the overall health and rate of survival during the winter season. Construction activities would lead to short-term negative effects to fisheries resources due to increased turbidity and noise/vibrations; however, most fish would vacate the area during construction and return when conditions are favorable. The RECOMMENDED PLAN would improve overwintering conditions for approximately 80 acres. INVASIVE SPECIES Impacts of the No-Action Alternative: There are several invasive species present in the project area. Moderate adverse impacts to the floodplain forest are expected to occur as reed canary grass, black locust, and other invasive species distribute and establish patches throughout the project area. The conversion of forest to dense monotypic patches of reed canary 67

79 grass would decrease the availability of important forest habitat. Other invasive species (e.g., zebra mussels, Eurasian milfoil, etc.) would be expected to have impacts similar in intensity to what is found in the project area currently. Impacts of the Recommended Plan: Invasive terrestrial species will be removed as part of the TSI measure. In addition, the planting of diverse tree species will add resilience to the forest and will ensure a closed canopy, which helps prevent the establishment of reed canary grass, which tends to colonize open patches of the forest. The structure at C1 and the various rock mounds and erosion protection would require the placement of riprap in the aquatic areas. The hard surfaces provided by these features are preferred by zebra mussels and would likely become colonized within the first couple years of placement. However, the increase in zebra mussels would be negligible relative to the zebra mussel population in the project area WATER QUALITY Impacts of the No-Action Alternative: Without action, the water quality and hydraulic characteristics of the project area would continue to deteriorate backwater overwintering conditions. Increasing flows and velocities, colder water, and sedimentation would be among the characteristics deficient for overwintering. In addition, water quality in the wetland adjacent to R4 would continue to be impacted by sedimentation. Impacts of the Recommended Plan: The recommended plan would have temporary, shortterm adverse impacts to water quality by increasing turbidity in the immediate project area where construction and excavation occur. Silt curtains and other BMPs would be used to contain the sediment plumes and localize impacts. C1 would reduce flow to improve overwintering habitat. The reduction in flow would likely decrease the amount of dissolved oxygen a minor amount. Project features were designed to balance velocity reduction and dissolved oxygen needs, reducing the likelihood that critically-low winter dissolved oxygen levels would occur. Should this be a problem in the future, project features can be altered through adaptive management to increases flows and oxygen levels. The dredged areas have been designed to optimize the residence time to balance temperature and dissolved oxygen needs. Improvements to water quality characteristics for overwintering fish communities would lead to long-term beneficial impacts for those populations, as mentioned previously, as well as lotic fishes, mussels, and macroinvertebrates. The recommended plan would also improve water quality in the two protected wetlands at R4 and W1. These wetlands would be disconnected from high flows and bedload, improving transparency. AIR QUALITY Impacts of the No-Action Alternative: The No-Action Alternative would have no impacts to air quality. Impacts of the Recommended Plan: Minor, temporary increases in airborne particulates are anticipated as a result of mobilization and use of construction equipment. Frequent inspections of construction equipment will be made during construction to ensure they are properly functioning and do not release unnecessary amounts of emissions HAZARDOUS, TOXIC, AND RADIOACTIVE WASTE Impacts of the No-Action Alternative: There are known PAH chemicals at the old highway embankment. These chemicals would not be disturbed in either the no-action or recommended plan. The area was avoided to avoid disturbance of these soils. 68

80 Impacts of the Recommended Plan: There are known PAH chemicals at the old highway embankment. These chemicals would not be disturbed in either the no-action or recommended plan. The area was avoided to avoid disturbance of these soils. A short-term risk for a fuel spill during construction activities would exist. The contractor would be required to have a spill prevention and clean-up plans and utilize BMPs during construction FLOODING EFFECTS Impacts of the No-Action Alternative: There would be no flood stage effects with the No- Action Alternative. Impacts of the Recommended Plan: There would be no flood stage effects with the Recommended Plan. Hydraulic models were run for alternatives early during plan formulation, and features that had any measurable effect on flood stage were eliminated HISTORICAL AND CULTURAL RESOURCES Impacts of the No-Action Alternative: No historic property impacts would be anticipated with the No-Action Alternative. Impacts of the Recommended Plan: The Upper Mississippi River floodplain has several landform types with the potential for historic properties (i.e. precontact or historic districts, archaeological sites, structures). The design of project features takes into account known historic properties within the Area of Potential Effect (APE). Construction of project features would have minimal to no ground disturbance. Most features would be constructed in shallow open water or existing low lying wetland and floodplain forest areas. No natural levees or islands would be impacted through ground disturbance but instead would be preserved through material placement and erosion protection adjacent to the existing landforms. Proposed features include access and habitat dredging within historic natural channels, rock erosion protection, establishment of floodplain forests through dredge placement, and tree plantings. Dredging would be restricted to natural river channels existing prior to the lock and dam system. Design of slope stability features where known archaeological resources are located was taken into consideration and restrictions were placed on dredging to protect existing shorelines containing archaeological resources from potential slumping or erosion. Construction of floodplain forest would be completed through mechanical or hydraulic dredging. Both actions would have minimal to no ground disturbance. No ground disturbance would occur within the boundaries of known archaeological resources. The proposed project was coordinated with the Wisconsin State Historic Preservation Office and Tribal Historic Preservation Offices with the determination of no historic properties affected SOCIOECONOMIC RESOURCES Impacts of the No-Action Alternative: Minor long-term adverse effects to socioeconomic resources would be expected. Human use of the project area would likely continue to decline as the ecosystem resources degrade. Impacts of the Recommended Plan: The Recommended Plan would have no measurable impacts on community cohesion; property values; industrial growth; or privately owned farms. The increase in recreational use with these alternatives would likely increase community, regional, and business growth; and tax revenues. The project would utilize a large quantity of dredged material from the Nine-Foot Navigation Channel. The use of this material would be a minor beneficial effect on the commercial navigation program. The commercial channel in the East Channel will also be dredged to obtain material for forest construction. This will also provide a minor beneficial effect. 69

81 In the long-term, habitat improvement would increase wetland wildlife and fish populations and diversity. This would, in turn, increase outdoor recreational opportunities including bird watching, hunting, and fishing. In the short-term construction activities would likely disturb recreational activities, but would also create short-term employment and business opportunities AESTHETICS Impacts of the No-Action Alternative: The no-action alternative would not result in effects to the area s aesthetics. Impacts of the Recommended Plan: Short-term impacts would occur with construction equipment and soil disturbance. In the long-term, aesthetic resources would improve as a result of vegetative plantings, higher quality habitat, and increased wetland wildlife NOISE LEVELS Impacts of the No-Action Alternative: No change in noise levels would be expected. Impacts of the Recommended Plan: Project Construction would result in temporary increases in noise levels associated with heavy equipment. This may temporarily displace some wildlife and decreased recreational use. No long-term impacts would be expected ENVIRONMENTAL JUSTICE An evaluation of environmental justice impacts is mandated by Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations (February 11, 1994). This Executive Order directs Federal agencies to identify and address, as appropriate, disproportionately high and adverse health or environmental effects of its programs, policies, and activities on minority and low-income populations. AFFECTED ENVIRONMENT The U.S. Environmental Protection Agency (USEPA) on-line EJScreen mapping tool (Version 2017) was used to characterize existing conditions for minority and low-income groups. The area used in the analysis is shown in Figure 14. The EJScreen tool estimated an approximate population of 7,522 in the area. The minority and linguistically isolated populations of the area are lower than the state and national averages. The minority population is 6%, while the state is 18% and the national average is 38%. The low-income population is within 4% of the state and national averages. The population over 64 years of age is 21%, while the state and national averages are both 14%. 70

82 Figure 14. Environmental Justice Mapping Tool. ENVIRONMENTAL EFFECTS Environmental Justice is a national goal and is defined as the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. Project goals and objectives were established to provide environmental restoration and enhance the quality of the environment for all people. Public involvement, via public meetings and distribution of information concerning the proposed project, has and will continue to be an integral part of planning for this project to ensure that concerns of all people will be fully considered in the decision-making process. Minority groups are a very small component of communities surrounding the project area (6%); however, the project itself would not have any permanent adverse effects on surrounding communities. There would be short-term adverse impacts to aesthetics, recreation, and transportation. These effects would occur in the floodplain, away from residential neighborhoods. Therefore, neither the no action alternative nor the proposed action would cause a disproportionate impact on any population GREENHOUSE GASES Carbon dioxide (CO 2) is the primary greenhouse gas emitted from human activities, chiefly through combustion of fossil fuels (EPA 2015). Greenhouse gases absorb reflected energy from the sun and warm Earth s atmosphere. Increases in greenhouse gases have resulted in measurable warming of the Earth s surfaces and ultimately changes to some ecosystems. Trees are able to reduce the amount of CO 2 in the atmosphere by sequestering the gas during photosynthesis and returning oxygen to the atmosphere as a byproduct. Impacts of the No-Action Alternative: The No-Action Alternative would not result in any impact to greenhouse gases. 71